People living with type 2 diabetes are significantly more likely to develop urinary tract infections (UTIs) than those without diabetes. These infections are often more severe, are more likely to return and can sometimes lead to serious complications if they are not recognised and treated promptly.
The reason is not simply that there is more sugar in the urine. Diabetes affects several of the body's natural defence mechanisms. Persistently raised blood glucose can reduce the ability of the immune system to fight bacteria, damage the nerves that control bladder emptying and alter the normal balance of bacteria living within the urinary tract. Together, these changes make it easier for bacteria to enter the bladder, multiply and cause infection.
Urinary tract infections are among the most common bacterial infections worldwide, affecting an estimated 150 million people every year. People with type 2 diabetes have a substantially higher risk of developing both uncomplicated bladder infections (cystitis) and more serious kidney infections (pyelonephritis). They are also more likely to experience recurrent infections, require hospital admission and develop infections caused by antibiotic-resistant bacteria.
Large population studies have shown that people with type 2 diabetes develop urinary tract infections considerably more often than those without diabetes. A UK study reported an incidence of approximately 47 urinary tract infections per 1,000 person-years in people with type 2 diabetes compared with around 30 per 1,000 person-years in those without diabetes. The risk increases further in older adults, women, people with poor blood sugar control and those who have developed diabetic complications affecting the bladder or kidneys.
The encouraging news is that many urinary tract infections can be prevented. Improving blood sugar control, recognising symptoms early, identifying risk factors, and using evidence-based preventive strategies can significantly reduce the risk of recurrent infections and help avoid unnecessary antibiotic use.
This article explains why type 2 diabetes increases the risk of urinary tract infections, how diabetes affects the bladder and immune system, which symptoms should never be ignored, how infections are diagnosed and treated, and the most effective ways to reduce the risk of future urinary tract infections using the latest evidence from NICE, the European Association of Urology (EAU) and recent international research.
What is the link between type 2 diabetes and urinary tract infections?
The relationship between type 2 diabetes and urinary tract infections (UTIs) has been recognised for decades. People with diabetes are not only more likely to develop urinary tract infections, but they are also more likely to experience recurrent infections, more severe infections and infections caused by antibiotic-resistant bacteria.
This increased risk is not caused by a single problem. Instead, diabetes affects several natural defence mechanisms that normally protect the urinary tract from infection. Raised blood glucose can impair the immune system, damage the nerves controlling bladder emptying, alter the bladder's protective environment and change the balance of bacteria living within the urinary and gastrointestinal tracts. Together, these changes create conditions that make it easier for bacteria to establish an infection.
Large population studies have consistently demonstrated this increased risk.
A UK study involving more than 100,000 adults with type 2 diabetes found that urinary tract infections occurred at a rate of approximately 46.9 cases per 1,000 person-years, compared with 29.9 cases per 1,000 person-years in people without diabetes. In practical terms, the finding means that people with type 2 diabetes develop urinary tract infections around 50–60% more often than those without diabetes.
The risk is even greater in people who:
- have poorly controlled blood sugar levels;
- have had diabetes for many years;
- have developed diabetic kidney disease;
- have diabetic nerve damage (diabetic neuropathy);
- are older;
- require urinary catheters; or
- have previously experienced recurrent urinary tract infections.
Women with diabetes are particularly affected because they already have a higher baseline risk of urinary tract infections due to female anatomy. When diabetes is added, these risks combine, making recurrent bladder infections considerably more common.
Importantly, diabetes increases the risk of both lower urinary tract infections, such as cystitis (a bladder infection), and upper urinary tract infections, such as pyelonephritis (a kidney infection). People with diabetes are also more likely to develop uncommon but potentially life-threatening infections, including emphysematous cystitis and emphysematous pyelonephritis, in which gas-forming bacteria infect the bladder or kidney.
Why does diabetes make infections more severe?
Diabetes affects much more than blood sugar.
Persistently raised glucose levels interfere with several parts of the body's immune response, making it harder for white blood cells to recognise, engulf and destroy bacteria. At the same time, damage to the small blood vessels can reduce blood flow to infected tissues, limiting the delivery of immune cells and antibiotics to the site of infection.
In many people, diabetes also affects the nerves supplying the bladder. As a result, the bladder may not empty completely, leaving residual urine behind after urination. Residual urine provides bacteria with more time to multiply, increasing the likelihood of both persistent and recurrent infections.
Recent research has also shown that diabetes alters the urinary microbiome—the community of naturally occurring microorganisms within the urinary tract. Although this area of research is still evolving, these changes may reduce the urinary tract's natural resistance to harmful bacteria and contribute to recurrent infections in susceptible individuals.
Does optimal blood sugar control reduce the risk?
Yes.
Many studies have shown that people who have better control over their blood sugar levels get sick less often than people who have high blood sugar levels all the time.
Keeping blood sugar within the recommended target range supports normal immune function, reduces glucose concentrations in the urine and may improve bladder function over time. Although good diabetic control cannot eliminate the risk of urinary tract infections, it remains one of the most effective long-term strategies for reducing both the frequency and severity of infections.
For many people, preventing recurrent urinary tract infections begins not with antibiotics, but with optimising diabetes management and identifying and addressing any underlying urological problems.
Why does type 2 diabetes increase the risk of urinary tract infections?
There is no single reason why people with type 2 diabetes develop more urinary tract infections. Instead, diabetes affects several of the body's natural defence mechanisms simultaneously. These changes make it easier for bacteria to enter the urinary tract, survive within the bladder and cause recurrent infections.
Understanding these mechanisms also explains why simply prescribing repeated antibiotics is often not enough. Long-term prevention requires addressing the underlying reasons why infections develop in the first place.
Does high blood sugar help bacteria grow?
Indirectly, yes.
When blood sugar levels remain high over prolonged periods, the kidneys may begin to remove excess glucose from the bloodstream into the urine. This is known as glycosuria, meaning glucose is present in the urine.
Glucose itself does not automatically cause an infection, but it may create a more favourable environment for some bacteria to multiply once they have entered the urinary tract.
More importantly, persistently raised blood sugar reflects diabetes that is placing stress on multiple body systems, including the immune system and bladder, both of which play a much greater role in determining whether an infection develops.
How does diabetes weaken the immune system?
Your immune system is the body's natural defence against infection.
One of its most important components is the white blood cell, which identifies, attacks and destroys invading bacteria.
Persistently high blood sugar reduces the efficiency of several white blood cell functions, including:
- recognising invading bacteria;
- moving rapidly to the site of infection;
- engulfing bacteria (phagocytosis); and
- killing bacteria once they have been captured.
Diabetes also causes chronic low-grade inflammation, a state in which the immune system remains persistently activated. Over time, this reduces its ability to mount an effective response against new infections.
As a result, bacteria that might normally be eliminated quickly have a greater opportunity to establish an infection within the bladder.
How does diabetes affect the bladder?
Diabetes can damage the nerves controlling the bladder, a condition known as diabetic cystopathy or diabetic bladder dysfunction.
When these nerves are affected, the bladder may:
- lose some of its normal sensation;
- become less efficient at contracting;
- empty more slowly; or
- fail to empty completely.
This leaves residual urine behind after passing urine.
Residual urine acts like stagnant water in a pond. Instead of being flushed away during urination, bacteria remain within the bladder for longer, giving them more time to attach to the bladder lining, multiply and trigger infection.
For many people with long-standing diabetes, incomplete bladder emptying is one of the most important reasons why urinary tract infections keep returning.
What is the urinary microbiome, and why does it matter?
For many years, doctors believed that healthy urine was completely sterile.
We now know that this assumption is not true.
The urinary microbiome is the collection of naturally occurring bacteria and other microorganisms that live within the urinary tract. Most of these organisms are harmless and may even help protect against infection by competing with disease-causing bacteria.
Emerging research suggests that diabetes can alter the composition of this microbiome. These changes may reduce the urinary tract's natural resistance to infection and make it easier for harmful bacteria, particularly Escherichia coli (E. coli), to establish themselves within the bladder.
Although this area of research is still developing, it is helping scientists better understand why some people experience recurrent urinary tract infections despite apparently appropriate treatment.
Can bacteria hide from antibiotics?
Yes.
One of the most important discoveries in urinary tract infection research over the past two decades is that some bacteria are capable of hiding within the bladder lining.
After attaching to the bladder wall, certain strains of E. coli can invade the surface cells of the bladder and form tiny protected communities known as intracellular bacterial communities.
These bacteria are shielded from both the immune system and many antibiotics. Even after symptoms improve, some bacteria may survive within the bladder lining before later re-emerging and causing another infection.
Scientists also know that bacteria can produce biofilms, thin protective layers that allow groups of bacteria to stick firmly to surfaces such as urinary catheters, bladder stones and the bladder lining. Biofilms make bacteria much more difficult to eradicate and contribute to recurrent infections and increasing antibiotic resistance.
Why are antibiotic-resistant infections more common in diabetes?
People with diabetes often receive more courses of antibiotics throughout their lifetime because they experience infections more frequently.
Repeated antibiotic exposure places pressure on bacteria to develop resistance, allowing those with survival advantages to multiply.
In addition, repeated hospital admissions, urinary catheter use and recurrent infections increase the likelihood of encountering bacteria that are naturally more resistant to commonly used antibiotics.
This is one reason why urine cultures are particularly important in people with diabetes who develop recurrent urinary tract infections. Identifying the bacteria responsible and selecting the most appropriate antibiotic helps improve treatment while reducing unnecessary exposure to ineffective antibiotics.
What does this finding mean for long-term management?
Understanding why diabetes increases the risk of urinary tract infections changes the focus of treatment.
Instead of simply treating each infection as it occurs, modern management aims to:
- optimise blood sugar control;
- improve bladder emptying where necessary;
- identify reversible risk factors;
- Use antibiotics appropriately;
- prevent recurrent infections using evidence-based strategies; and
- reduce the development of antibiotic resistance.
This personalised approach not only reduces the frequency of urinary tract infections but also improves long-term bladder health and quality of life.
What are the symptoms of a urinary tract infection in people with type 2 diabetes?
People with type 2 diabetes usually experience the same urinary symptoms as people without diabetes. However, infections may be more severe, more likely to spread to the kidneys and sometimes more difficult to recognise, particularly in older adults or those with diabetic nerve damage.
Recognising the symptoms early is important because prompt treatment can reduce the risk of complications and hospital admission.
What are the common symptoms?
Most urinary tract infections affecting the bladder (cystitis) cause one or more of the following symptoms:
- burning or stinging when passing urine (dysuria);
- needing to pass urine more frequently than usual;
- a sudden, urgent need to urinate;
- passing only small amounts of urine;
- discomfort or pressure in the lower abdomen;
- cloudy or unpleasant-smelling urine; and
- blood in the urine (haematuria).
These symptoms occur because bacteria trigger inflammation of the bladder lining, making the bladder more sensitive and reducing the amount of urine it can comfortably hold.
Can diabetes make symptoms less obvious?
Yes.
Long-standing diabetes can damage the nerves supplying the bladder, reducing bladder sensation. As a result, some people may experience fewer typical symptoms despite having a significant infection.
Older adults may also present differently, sometimes developing:
- increasing tiredness;
- reduced appetite;
- worsening blood sugar control;
- general weakness;
- confusion, particularly in frail individuals; or
- a general feeling of being unwell rather than obvious urinary symptoms.
Because these symptoms are non-specific, urinary tract infections should be considered alongside other possible causes rather than being assumed to be the explanation.
What are the symptoms of a kidney infection?
If bacteria spread from the bladder to the kidneys, a kidney infection (pyelonephritis) can develop.
Symptoms usually include:
- fever above 38°C;
- chills or shivering;
- pain in the side or back below the ribs (loin pain);
- nausea or vomiting;
- feeling generally very unwell; and
- sometimes worsening urinary symptoms.
Kidney infections occur more frequently in people with diabetes than in the general population and require prompt treatment because they can progress rapidly.
Can diabetes affect blood sugar during an infection?
Yes.
Any infection places stress on the body.
During a urinary tract infection, the body releases stress hormones that make it more difficult for insulin to lower blood glucose levels. As a result, blood sugar often rises, even in people whose diabetes is usually well controlled.
Some people first realise they have an infection because they notice:
- unexpectedly high blood glucose readings;
- increased thirst;
- passing urine more frequently than usual;
- fatigue; or
- greater difficulty keeping blood sugar within their normal target range.
For people using continuous glucose monitoring (CGM), an unexplained and persistent rise in glucose levels may occasionally be an early clue that an infection is developing.
When should people with diabetes seek urgent medical attention?
People with diabetes should seek urgent assessment if they develop symptoms suggesting that the infection may have become more serious.
These include:
- fever with shaking chills;
- severe pain in the back or side;
- persistent vomiting;
- confusion or reduced consciousness;
- inability to pass urine;
- severe dehydration;
- rapidly rising blood glucose despite usual treatment; or
- symptoms suggesting sepsis, such as extreme drowsiness, rapid breathing or severe illness.
Although most urinary tract infections remain uncomplicated, people with diabetes have a higher risk of developing serious infections than those without diabetes. Early recognition and treatment can significantly reduce the likelihood of complications.
Can a urinary tract infection be the first sign of diabetes?
Sometimes, yes.
Although most urinary tract infections occur in people with an established diagnosis of diabetes, recurrent or unusually severe infections can occasionally be the first indication of previously undiagnosed type 2 diabetes.
If someone experiences repeated urinary tract infections together with excessive thirst, passing large amounts of urine, unexplained weight loss or persistent fatigue, testing for diabetes may be appropriate.
Recognising diabetes at an early stage allows treatment to begin before complications develop and may also reduce the likelihood of future urinary tract infections.
How are urinary tract infections diagnosed in people with type 2 diabetes?
Most urinary tract infections (UTIs) in people with type 2 diabetes are diagnosed using a combination of symptoms, urine testing and, when appropriate, laboratory investigations. However, because diabetes increases the risk of recurrent infections, antibiotic-resistant bacteria and complications, the assessment is often more comprehensive than for someone without diabetes.
The aim is not only to confirm that a urinary tract infection is present, but also to identify the bacteria responsible, assess the severity of the infection and determine whether there is an underlying problem that is increasing the risk of recurrent infections.
Is a urine dipstick enough?
A urine dipstick is often the first test performed because it provides results within a few minutes.
The dipstick looks for several markers, including:
- leucocytes (white blood cells), which suggest inflammation;
- nitrites, which indicate that certain bacteria are present;
- blood;
- protein; and
- glucose.
Although dipsticks are useful screening tools, they have important limitations.
A positive dipstick supports the diagnosis of a urinary tract infection, but it does not identify the specific bacteria causing the infection or determine which antibiotics are likely to be effective. Likewise, a negative dipstick does not completely exclude infection, particularly if symptoms are typical or the bacteria do not produce nitrites.
For this reason, urine dipsticks should always be interpreted alongside the patient's symptoms and medical history.
Why is a urine culture particularly important in diabetes?
A urine culture is one of the most valuable investigations for people with diabetes who develop a urinary tract infection.
Unlike a dipstick, a urine culture identifies:
- the exact bacteria causing the infection;
- the number of bacteria present;
- which antibiotics are likely to be effective; and
- whether antibiotic-resistant organisms are involved.
Because people with diabetes have a higher risk of recurrent infections and resistant bacteria, urine culture is recommended more often than in uncomplicated urinary tract infections affecting otherwise healthy individuals.
Culture results also help avoid unnecessary antibiotic use by ensuring that treatment is targeted to the bacteria responsible rather than relying on repeated empirical antibiotic prescriptions.
What blood tests might be needed?
Blood tests are not required for every urinary tract infection.
However, they may be recommended if there are concerns about a more serious infection or if hospital admission is being considered.
Common blood tests include:
- full blood count (FBC) to assess the body's response to infection;
- C-reactive protein (CRP), a marker of inflammation;
- kidney function tests (creatinine and estimated glomerular filtration rate [eGFR]);
- blood glucose levels; and
- blood cultures if sepsis is suspected.
These investigations help determine the severity of the infection and guide treatment decisions.
When are scans needed?
Imaging is not routinely required for every urinary tract infection.
However, people with diabetes are more likely to undergo imaging if:
- infections keep recurring;
- symptoms fail to improve with appropriate treatment;
- kidney stones are suspected;
- there is concern about urinary obstruction;
- blood is repeatedly present in the urine;
- kidney infection is suspected; or
- an unusual or severe infection is suspected.
Depending on the situation, investigations may include:
- ultrasound, to assess the kidneys and bladder;
- CT scanning, particularly when stones, obstruction or emphysematous infections are suspected; or
- occasionally, MRI for selected complex cases.
These tests help identify structural problems that may require treatment in addition to antibiotics.
Do people with diabetes need cystoscopy?
Not usually.
A flexible cystoscopy—a procedure in which a thin camera is passed through the urethra to examine the bladder—is not performed routinely for every urinary tract infection.
However, it may be recommended if:
- blood in the urine persists after the infection has resolved;
- recurrent infections continue despite appropriate treatment;
- bladder stones are suspected;
- there are symptoms suggesting bladder outlet obstruction;
- imaging has identified an abnormality; or
- there is concern about bladder cancer or another bladder disorder.
The purpose of cystoscopy is to identify an underlying cause rather than to diagnose the infection itself.
Should the bladder be checked for incomplete emptying?
Yes, particularly in people with long-standing diabetes.
Diabetes can damage the nerves that control bladder function, which can lead to diabetic bladder dysfunction. As a result, the bladder may not empty completely, leaving residual urine behind after urination.
Residual urine provides bacteria with an opportunity to multiply and is an important cause of recurrent urinary tract infections.
A simple bladder scan, performed immediately after passing urine, can measure the amount of urine that remains in the bladder. Identifying incomplete bladder emptying may entirely change the long-term management plan by addressing the underlying problem rather than repeatedly treating infections with antibiotics.
Why is finding the underlying cause crucial?
For many people with type 2 diabetes, treating a urinary tract infection is only the first step.
If infections keep coming back, it’s important to find out why.why.
Possible contributing factors include:
- poor blood sugar control;
- diabetic bladder dysfunction;
- enlarged prostate in men;
- kidney or bladder stones;
- urinary obstruction;
- urinary catheters;
- menopause in women; and
- structural abnormalities of the urinary tract.
Addressing these underlying factors can significantly reduce the risk of future infections and may be more effective than repeated courses of antibiotics alone.
Modern management therefore focuses not only on treating the current infection but also on preventing the next one through a personalised, evidence-based approach.
How are urinary tract infections treated in people with type 2 diabetes?
Most urinary tract infections in people with type 2 diabetes are treated successfully with antibiotics, but treatment should be tailored to the individual. The choice depends on whether the infection involves the bladder or kidneys, how unwell the person is, kidney function, previous urine cultures and whether antibiotic-resistant bacteria have been identified before.
Diabetes does not automatically mean that every urinary tract infection is complicated or requires hospital treatment. However, infections deserve careful assessment because diabetes can increase the likelihood of recurrence and serious complications in some patients.
Why is a urine culture important before choosing antibiotics?
Whenever appropriate, obtaining a urine sample before antibiotics are started can be particularly useful in people with diabetes who have recurrent, severe or complicated infections.
A urine culture identifies the bacteria responsible and shows which antibiotics are likely to work.
This matters because repeated antibiotic exposure increases the likelihood of antimicrobial resistance, meaning bacteria become resistant to medicines that previously killed them.
Once culture results become available, treatment can be changed if necessary to use the narrowest effective antibiotic. This is an important principle of antimicrobial stewardship—treating the infection effectively while limiting unnecessary antibiotic exposure.
Does kidney function affect which antibiotic can be used?
Yes.
Diabetes is an important cause of chronic kidney disease, and several antibiotics used for urinary tract infections are removed from the body through the kidneys.
Kidney function therefore needs to be considered when choosing an antibiotic and its dose. Some antibiotics become less suitable when kidney function is significantly reduced, while others require dose adjustment.
This is one reason why the same antibiotic is not appropriate for every person with diabetes and a UTI.
What if the infection has reached the kidneys?
A kidney infection (pyelonephritis) requires more intensive treatment than uncomplicated cystitis.
People with fever, loin pain, vomiting or significant systemic illness may require blood tests, urine culture and sometimes imaging.
Those who are severely unwell, dehydrated, unable to take tablets or showing signs of sepsis may require admission to hospital for intravenous fluids and antibiotics.
In people with diabetes, clinicians also have a lower threshold for considering unusual complications such as obstruction, kidney abscess or emphysematous pyelonephritis, a rare but serious infection in which gas-forming bacteria infect the kidney.
Should bacteria in the urine always be treated in someone with diabetes?
No. This is an important distinction.
Asymptomatic bacteriuria means bacteria are found in the urine even though the person has no urinary symptoms.
It is more common in people with diabetes, particularly women, but finding bacteria does not automatically mean there is an infection requiring treatment.
Current European guidance recommends against routinely treating asymptomatic bacteriuria in people with well-controlled diabetes. Unnecessary treatment offers no benefit and exposes patients to antibiotic side effects and antimicrobial resistance.
Important exceptions include situations such as pregnancy and before certain urological procedures where the urinary tract lining will be breached.
The principle is therefore simple:
Treat the patient and the clinical infection—not a urine result in isolation.
Do SGLT2 inhibitors cause urinary tract infections?
This question deserves particular attention because SGLT2 inhibitors such as dapagliflozin and empagliflozin deliberately increase the amount of glucose passed into the urine.
These medicines have major benefits for selected people with type 2 diabetes, heart failure and chronic kidney disease, but they clearly increase the risk of genital fungal infections, such as thrush.
The relationship with bacterial urinary tract infections is much less clear.
Recent large analyses have produced differing estimates. Some randomised-trial analyses suggest a small increase in overall UTI risk, while other studies have found a negligible increase. Importantly, a large real-world meta-analysis involving almost 680,000 people did not observe an increased risk of severe UTI compared with other glucose-lowering treatments.
This distinction matters:
genital fungal infection and bacterial urinary tract infection are not the same condition.
Therefore, developing a UTI while taking an SGLT2 inhibitor does not automatically mean the medicine caused it or that the treatment should permanently be stopped.
Why should repeated antibiotic treatment be avoided where possible?
Repeated courses of antibiotics can select increasingly resistant bacteria and alter the normal bacterial communities within the bowel, genital tract and urinary system.
For someone experiencing repeated infections, the question should therefore gradually change to:
“Which antibiotic should I take next?”
to:
“Why do these infections keep happening, and can we prevent them?”
That may involve improving diabetes control, checking whether the bladder empties properly, treating urinary obstruction, addressing postmenopausal changes, removing stones where relevant and considering evidence-based strategies for preventing recurrent urinary tract infections.
The long-term goal is not simply to treat each infection successfully but to reduce the likelihood of the next infection occurring.
How can people with type 2 diabetes prevent recurrent urinary tract infections?
Preventing recurrent urinary tract infections (UTIs) in people with type 2 diabetes requires more than simply drinking more water or taking repeated courses of antibiotics.
The most effective approach is to identify and correct the factors that make infection more likely. These may include poor blood sugar control, incomplete bladder emptying, menopause, urinary obstruction, stones or repeated exposure to antibiotics.
A recurrent UTI is generally defined as two or more infections within six months or three or more within 12 months.
Research specifically examining people with type 2 diabetes has reported recurrence rates of approximately 23–37%, although studies vary considerably in their populations and definitions.
Does better blood sugar control reduce recurrent UTIs?
Good blood sugar control is an important part of prevention.
Persistently raised glucose affects immune function and may increase glucose within the urine. Long-standing diabetes can also damage the nerves controlling the bladder, increasing the likelihood of incomplete emptying.
Observational studies consistently associate poorer glycaemic control with greater UTI risk. However, it is important not to overstate the evidence: we do not yet have strong clinical trial evidence showing that lowering HbA1c by a particular amount produces a specific percentage reduction in recurrent UTIs.
The practical message is therefore not that there is a special HbA1c target for preventing UTIs. Instead, maintaining good diabetes control removes one important factor that can make infections more likely.
Why is bladder emptying important?
Every time the bladder empties properly, urine helps remove bacteria from the urinary tract.
Diabetes can damage the nerves controlling bladder sensation and contraction. Some people therefore retain a significant amount of urine after urinating without realising it.
This residual urine provides bacteria with more time to multiply.
For someone with diabetes and repeated UTIs, checking bladder emptying with a simple bladder scan can therefore be more useful than repeatedly changing antibiotics.
In men, an enlarged prostate may also prevent complete emptying. Treating the obstruction can sometimes substantially reduce recurrent infections.
Does drinking more water prevent UTIs?
Adequate hydration is sensible, particularly for people who habitually drink very little.
Drinking more fluid increases urine production and bladder emptying, which may reduce the opportunity for bacteria to remain within the urinary tract.
However, more is not always better. Excessive fluid intake has not been shown to provide additional protection and can worsen urinary frequency, urgency and night-time urination.
The aim should be appropriate hydration rather than attempting to continually “flush” the bladder.
Why is menopause important in women with diabetes?
After the menopause, falling oestrogen levels change the tissues and normal bacterial environment around the vagina and urethra.
Protective Lactobacillus bacteria decline and the vaginal environment becomes less acidic, making it easier for organisms such as E. coli to colonise the area and enter the bladder.
Diabetes adds another layer of risk.
For postmenopausal women with recurrent UTIs, vaginal oestrogen is one of the better-supported non-antibiotic preventive treatments.
NICE recommends considering vaginal oestrogen when behavioural and personal hygiene measures alone have not been effective. Evidence reviewed by NICE found relatively low numbers needed to treat (NNT) in older studies: approximately 3 women treated with topical oestrogen cream to prevent one recurrence, although the underlying studies were small and these figures should be interpreted cautiously.
What other problems should be corrected?
Recurrent infections may sometimes be driven by a treatable urological problem rather than diabetes itself.
Depending on the individual, this may include:
- incomplete bladder emptying;
- an enlarged prostate;
- kidney or bladder stones;
- urinary tract obstruction;
- long-term urinary catheters;
- constipation;
- urinary incontinence; or
- an anatomical abnormality of the urinary tract.
Correcting one of these problems may be considerably more effective than repeatedly treating each infection after it develops.
Are non-antibiotic treatments available?
Yes.
For people who continue to experience recurrent UTIs despite addressing reversible risk factors, several non-antibiotic preventive strategies may be considered.
These include options such as:
- vaginal oestrogen after the menopause;
- methenamine hippurate (Hiprex®);
- Canephron
- UTIPro AF
- selected immunomodulatory approaches;
- cranberry preparations;
- D-mannose; and
- bladder treatments such as hyaluronic acid, in selected patients.
However, these treatments do not all have the same quality of evidence, and some are supported much more strongly than others.
Rather than comparing them superficially here, they are better considered individually according to the patient's circumstances, kidney function, previous infections and the available evidence.
Should preventive antibiotics be used?
Long-term or targeted antibiotic prophylaxis can reduce recurrent UTIs in selected patients, but it has disadvantages.
Repeated antibiotic exposure can:
- select antibiotic-resistant bacteria;
- cause medication side effects;
- alter normal bacterial communities; and
- make subsequent infections more difficult to treat.
Current management therefore increasingly uses a stepwise approach: identify reversible causes first, consider appropriate non-antibiotic strategies and reserve antibiotic prophylaxis for selected patients when the expected benefits outweigh these disadvantages.
What is the most important message for someone with diabetes and recurrent UTIs?
Repeated UTIs should not automatically lead to repeated antibiotics without asking why the infections are recurring.
For someone with type 2 diabetes, prevention should focus on four areas:
- Optimise diabetes control.
- Make sure the bladder empties properly.
- Identify and treat contributing urological or menopausal factors.
- Use evidence-based preventive treatments when infections continue to recur.
This approach targets the conditions that allow infections to develop rather than simply treating each infection after it has occurred.
Frequently asked questions about diabetes and urinary tract infections
Why do people with type 2 diabetes get more urinary tract infections?
Type 2 diabetes can increase UTI risk in several ways. Persistently high blood sugar can impair the immune response, glucose may appear in the urine, and diabetic nerve damage can prevent the bladder from emptying completely. Residual urine gives bacteria more opportunity to multiply.
The important point is that sugar in the urine is only one part of the explanation.
Can high blood sugar cause a UTI?
High blood sugar does not directly cause a urinary tract infection—bacteria cause most UTIs.
However, persistently high glucose can make infection more likely by affecting immune function, increasing glucose in the urine and contributing to diabetic bladder dysfunction.
Can a UTI make my blood sugar rise?
Yes.
During an infection, the body releases stress hormones that can make insulin less effective. Blood glucose may therefore rise temporarily, even when diabetes is normally well controlled.
An unexplained deterioration in glucose control can sometimes accompany an infection, although high glucose readings alone do not prove that a UTI is present.
Are urinary tract infections more dangerous if I have diabetes?
They can be.
Most people with diabetes and a UTI recover without serious complications. However, diabetes is an important risk factor when assessing the likelihood of a more difficult clinical course. Kidney infection, sepsis and rare gas-forming infections such as emphysematous cystitis or emphysematous pyelonephritis deserve particular attention.
Current European guidance increasingly assesses UTIs according to whether infection is localised or systemic and the patient's individual risk factors, rather than assuming that every person with diabetes has the same degree of risk.
Do bacteria in my urine always mean I have a UTI?
No.
Asymptomatic bacteriuria means bacteria are found in the urine without symptoms of a urinary tract infection.
This is particularly important in diabetes because asymptomatic bacteriuria is more common, especially in women.
For most non-pregnant adults, antibiotics are not recommended simply because bacteria are found in the urine without symptoms. NICE specifically advises against treating asymptomatic bacteriuria routinely in men and non-pregnant women.
Treating bacteria unnecessarily can cause side effects and increase antibiotic resistance without providing clinical benefit.
Do diabetes medicines such as dapagliflozin or empagliflozin cause UTIs?
Not necessarily.
SGLT2 inhibitors, including dapagliflozin and empagliflozin, increase glucose excretion into the urine. They clearly increase the likelihood of genital fungal infections, such as thrush.
The relationship with bacterial UTIs is less straightforward. Large studies have not consistently demonstrated an important increase in serious bacterial urinary tract infections.
A genital fungal infection and a bacterial UTI are therefore not the same condition, even though both can occur while taking these medicines.
Why do my UTIs keep coming back?
Recurrent infections may result from several factors acting together.
In people with diabetes, important possibilities include:
- poor blood sugar control;
- incomplete bladder emptying caused by diabetic nerve damage;
- menopause;
- an enlarged prostate in men;
- urinary stones or obstruction;
- urinary catheters;
- resistant bacteria; and
- previous recurrent infections.
Recurrent UTI is generally defined as two or more infections within six months or three or more within 12 months.
Finding the reason for recurrence is often more useful than repeatedly changing antibiotics.
Can better diabetes control stop recurrent UTIs completely?
Not necessarily.
Effective diabetes control is an important part of reducing infection risk, but UTIs are influenced by many factors. There is currently no reliable evidence that reducing HbA1c by a particular percentage will prevent a specific number of infections.
Good glycaemic control should therefore form one part of a broader prevention strategy, rather than being presented as a cure for recurrent UTIs.
Diabetes and urinary tract infections: myths and facts
Myth: UTIs in diabetes are caused simply by sugar in the urine.
Fact: Glycosuria may contribute, but diabetes also affects immune function, bladder emptying and other natural defences against infection.
Myth: Every person with diabetes and bacteria in their urine needs antibiotics.
Fact: Bacteria without urinary symptoms usually represent asymptomatic bacteriuria. In most non-pregnant adults, treating this unnecessarily provides no benefit and contributes to antimicrobial resistance.
Myth: Every UTI in someone with diabetes is automatically a severe infection.
Fact: Most remain localised and respond to appropriate treatment. Diabetes is a risk factor that needs to be considered alongside symptoms, kidney function, urinary abnormalities and the person's general health.
Myth: SGLT2 inhibitors always cause urinary tract infections.
Fact: These medicines clearly increase genital fungal infections, but evidence for a major increase in bacterial UTIs is much less consistent.
Myth: Repeated antibiotics are the only way to prevent recurrent UTIs.
Fact: Prevention may involve improving bladder emptying, optimising diabetes control, treating urinary obstruction or stones, addressing menopausal changes and considering appropriate non-antibiotic preventive treatments.
Type 2 diabetes and urinary tract infections: key points
Type 2 diabetes increases the risk of urinary tract infections, but the relationship is much more complex than simply having excess sugar in the urine.
Diabetes can alter immune function, bladder emptying and the urinary environment, creating several opportunities for bacteria to establish or repeatedly cause infection. This helps explain why some people experience recurrent cystitis while others develop more severe infections involving the kidneys.
The most effective approach therefore has two objectives: treat the current infection correctly and identify why it developed.
For someone experiencing recurrent UTIs, this may mean reviewing diabetes control, measuring how well the bladder empties, identifying stones or obstruction, considering menopausal changes and using preventive strategies supported by evidence.
Equally important is avoiding unnecessary treatment. Bacteria in the urine without symptoms usually do not require antibiotics, and repeated antibiotic exposure can contribute to resistance.
Modern UTI management in people with type 2 diabetes is therefore increasingly personalised: recognising the individual's risk factors, distinguishing a simple localised bladder infection from systemic illness, using antibiotics appropriately and focusing on preventing the next infection rather than repeatedly treating infections after they occur.
About Mr Edward Calleja
Mr Edward Calleja is a consultant urological surgeon with a specialist interest in urinary tract infections, recurrent cystitis, prostatitis, enlarged prostate and robotic surgery for prostate and bladder cancer.
He has a particular interest in identifying the underlying causes of recurrent urinary tract infections and using evidence-based strategies to reduce repeated antibiotic exposure. This includes assessing bladder emptying, urinary obstruction and other urological factors that may contribute to recurrent infections in people with conditions such as diabetes.
His patient information articles are based on current NICE, European Association of Urology (EAU) guidance and peer-reviewed medical research, with complex evidence explained in clear language for patients.
References
Clinical guidelines
- European Association of Urology (EAU). EAU Guidelines on Urological Infections. European Association of Urology.
https://uroweb.org/guidelines/urological-infections - National Institute for Health and Care Excellence (NICE). Urinary tract infection (lower): antimicrobial prescribing. NICE guideline NG109.
https://www.nice.org.uk/guidance/ng109 - National Institute for Health and Care Excellence (NICE). Urinary tract infection (recurrent): antimicrobial prescribing. NICE guideline NG112.
- https://www.nice.org.uk/guidance/ng112
Diabetes and urinary tract infection
- Paudel S, John PP, Poorbaghi SL, Randis TM, Kulkarni R. Systematic Review of Literature Examining Bacterial Urinary Tract Infections in Diabetes. Journal of Diabetes Research. 2022;2022:3588297. doi:10.1155/2022/3588297.
https://pmc.ncbi.nlm.nih.gov/articles/PMC9130015/ - Confederat LG, Condurache MI, Alexa RE, Dragostin OM. Particularities of Urinary Tract Infections in Diabetic Patients: A Concise Review. Medicina (Kaunas). 2023;59(10):1747. doi:10.3390/medicina59101747.
https://pmc.ncbi.nlm.nih.gov/articles/PMC10608443/ - Papp SB, Christie AL, Zimmern PE. Characteristics of Nationwide Urinary Tract Infection (UTI) Visits by Age and Type II Diabetes Status in Women. Cureus. 2023;15(9). doi:10.7759/cureus.46000.
https://pmc.ncbi.nlm.nih.gov/articles/PMC10601984/
Recurrent urinary tract infection and bacterial persistence
- Cornelius SA, Basu U, Zimmern PE, De Nisco NJ. This article discusses overcoming challenges in the management of recurrent urinary tract infections. Expert Review of Anti-infective Therapy. 2024;22(12):1157–1169. doi:10.1080/14787210.2024.2412628.
https://pmc.ncbi.nlm.nih.gov/articles/PMC11634670/
SGLT2 inhibitors, diabetes and urinary tract infection
- Xu L, Wu Y, Li J, Ding Y, Chow J, Li L, Liu H, Wang Z, Gong T, Li Y, Ma G. Efficacy and safety of 11 sodium-glucose cotransporter-2 inhibitors at different dosages in type 2 diabetes mellitus patients inadequately controlled with metformin: a Bayesian network meta-analysis. BMJ Open. 2025;15(2). doi:10.1136/bmjopen-2024-088687.
https://pmc.ncbi.nlm.nih.gov/articles/PMC11877256/ - Shin H, Paik JM, Everett BM, DiCesare E, Alix C, Glynn RJ, Wexler DJ, Patorno E. Comparative Effectiveness of Individual Sodium-Glucose Cotransporter 2 Inhibitors. JAMA Internal Medicine. 2025;185(3):302–313. doi:10.1001/jamainternmed.2024.7357.
https://pmc.ncbi.nlm.nih.gov/articles/PMC11877166/ - Wang HW, Tsai MH, Fang YW, Lu KC, Wang J, Lu CL. Association between sodium-glucose cotransporter 2 inhibitor use and clinical outcomes in patients with type 2 diabetes after urinary tract infection. Diabetes, Obesity and Metabolism. 2025;27(11):6188–6199. doi:10.1111/dom.70003.
https://pmc.ncbi.nlm.nih.gov/articles/PMC12515756/ - Wu MZ, Guo R, Chandramouli C, et al. Urinary tract infection and continuation of sodium-glucose cotransporter-2 inhibitors in diabetic patients. European Heart Journal. Published online 17 October 2025. doi:10.1093/eurheartj/ehaf788.
https://academic.oup.com/eurheartj/article/doi/10.1093/eurheartj/ehaf788/8290387
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