UTIs in women: symptoms, risk factors and treatment

Urinary tract infections (UTIs) in the UK affect around half of all women at some point in their lifetime. They are the most common bacterial infection treated by GPs. Most UTIs are mild and can be treated at home. However, a minority of women, often those aged over 70, are admitted to hospital due to a UTI. 

Here, we’ll explore UTI symptoms, risk factors and treatment, as well as how to reduce your risk of UTIs. 

UTI symptoms in women

The most common symptoms of a UTI are the same in men and women. They include:

• A burning sensation when urinating
• Cloudy urine
• Pain or discomfort in your lower abdomen
• Urinating more often than usual

In some cases, you may notice blood in your urine. 

If the infection is not caught and treated early, it can spread to your kidneys and cause more severe symptoms. This includes: 

• Fatigue
• Feeling weak and generally unwell 
• Fever
• Pain around your kidneys ie in your upper back, below your ribcage
• Pain in your pelvic and groin area

In the most severe cases, the infection can spread to your blood and cause sepsis. This must be treated in hospital, with antibiotics given directly into the bloodstream (intravenous antibiotics). 

UTI causes 

The vast majority of UTIs are caused by infection with the bacteria Escherichia coli (E. coli), which lives in the large bowel. 

However, UTIs can also be caused by infection with other bacteria, namely Enterococcus faecalis, Klebsiella pneumoniae, Proteus mirabilis and Staphylococcus saprophyticus. Most of these bacteria are also found in the gut. 

In rare cases, a UTI can be caused by infection with a fungus, usually the yeast Candida albicans.

Health conditions linked to UTIs

Certain health conditions can lead to UTIs. These include: 

• A dilated ureter — widening of the tube that connects the kidneys to the bladder
• Kidney stones and bladder stones
• Kidney conditions present from birth eg bifid kidney
• Narrowing of the urethra — the tube that carries urine out of your body
• Neurogenic bladder — poor bladder control due to nerve problems

UTI risk factors in women

Risk factors for UTIs in women depend on your age and hormones. 

Risk factors in young women

In young women, UTIs are often caused by sexual intercourse. This is because, in women, the opening of the tube that urine leaves the body through (urethra) is close to both the vagina and the anus. Movement during sexual intercourse makes it easier for bacteria from these areas to spread to the urethra. 

Risk factors in middle-aged women

In middle-aged women, common risk factors for UTIs include: 

• Diabetes — uncontrolled diabetes can cause high sugar levels in the urine (glycosuria), which provides a food source for bacteria so they can multiply
• Constipation — when your bowel is full of hard stools, it can put pressure on your bladder that prevents it from emptying fully, which is a risk factor for UTIs; hard stools also contain more bacteria
• Incomplete bladder emptying — this allows a pool of urine to remain in your bladder for too long, which gives bacteria in your urine more time to multiply

Risk factors in post-menopausal women

In post-menopausal women, hormonal changes increase the risk of infection. Specifically, the decrease in oestrogen changes the environment in the vagina and urethra, making them less acidic. This makes it easier for bacteria to grow. 

Hormonal changes also cause the lining of the urethra to become thinner, drier and more fragile. The urethra can shorten and weaken the muscles that control its opening. All of these changes make it easier for bacteria to infect the urethra and travel up to the bladder. 

Another risk factor for UTIs in post-menopausal women is pelvic organ prolapse, where organs in the pelvic area, such as the bladder, rectum or womb, drop down or bulge into the vagina. 

Pelvic organ prolapse is more likely to happen after menopause due to hormonal changes that weaken the muscles, ligaments and connective tissues that hold organs in the pelvis in place. This can change how your organs are positioned, making it more likely that your bladder will not fully empty after urinating and, therefore, easier for bacteria to multiply in the urine left behind. 

General risk factors in women

Your risk of UTIs is higher if you don’t stay well hydrated. When you’re dehydrated, you urinate less often and are more likely to become constipated. 

Urinating regularly protects you against UTIs as urination flushes bacteria out of your urethra before they have time to multiply and cause an infection. On the other hand, urinating less can increase your risk of UTIs. 

Constipation increases your risk of UTIs in 2 ways: hard stools contain more bacteria, and a bowel full of hard stools pushing against the bladder stops it from emptying completely.

Why are UTIs more common in women than in men?

Women have a higher risk of UTIs than men because their urethra is shorter, which makes it easier for bacteria to spread upwards and, in some cases, into the bladder.

In women, the urethra is 3–4 cm long, while in men, it’s 15–20 cm long.
In women, the opening of the urethra is also in close proximity to the anus and vagina, making it easier for bacteria in these areas to spread to the urethra. In men, the opening of the urethra is at the tip of the penis.

Diagnosing UTIs

Symptoms of a UTI can overlap with other conditions, which is why getting a confirmed diagnosis is important. 

For example, a burning sensation when you urinate could be caused by acidic urine, which is treated with potassium citrate crystals or syrups. 

Frequent urination could be caused by an overactive bladder, which is treated with bladder training. 

Frequent urination alongside pelvic pain could be caused by painful bladder syndrome (interstitial cystitis), which is not due to infection and is not treated with antibiotics.

Tests for a suspected UTI

It’s important to diagnose a UTI with a urine test. This checks for bacteria in the urine. Bacteria from the urine can then be grown (cultured) to find out which bacteria is causing the infection. 

In addition to recommending that you have a urine test, your GP may perform a physical examination, where they gently press a hand against (palpate) your abdomen. This allows them to check whether there’s any swelling, tenderness or discomfort around your bladder and kidneys. 

In some cases, your GP may refer you for an ultrasound scan to check the health of your kidneys and to see if your bladder is emptying fully. This is a non-invasive imaging test that involves scanning your bladder and kidneys with a handheld ultrasound probe. 

To check how your bladder is emptying, you’ll be scanned before and after you urinate — this is called a post-void residual scan.

UTI treatment

If you are diagnosed with a UTI, you may be prescribed a short course of antibiotics to help clear the infection. You need to complete the course of antibiotics, even if your symptoms improve or go away while taking the antibiotics. 

In addition to completing a course of antibiotics, it’s helpful to stay well-hydrated and empty your bladder regularly. Your doctor may also provide advice and guidance to reduce your risk of developing a UTI based on your age, symptoms and general health. 

In some cases, you may need to have additional tests, such as a blood test or cystoscopy. 

Your doctor may recommend a kidney function blood test if you have severe symptoms to check if the infection has spread to your kidneys (pyelonephritis) and/or is affecting the ability of your kidneys to work properly.

If you have recurrent UTIs, your doctor may recommend a cystoscopy. This is where a very thin tube with a light and a camera on the end (cystoscope) is inserted into your urethra and passed into your bladder. This allows your doctor to check whether your bladder is inflamed and look for other physical abnormalities in your urethra and bladder lining. 

Recurrent UTI treatment

Recurrent UTIs occur when you have: 

• A UTI that returns immediately after treatment
• 2 or more UTIs in 6 months
• 3 or more UTIs in 12 months

As with any confirmed UTI, you will usually be given a course of antibiotics. However, if you have recurrent UTIs, you may also need further investigations to uncover the underlying cause of your recurrent UTIs. This usually involves having a cystoscopy. 

You may also be given prophylactic antibiotics, such as nitrofurantoin or trimethoprim. These antibiotics are given at very low doses and taken daily to prevent UTIs. An alternative to low-dose antibiotics is methenamine hippurate, which is an antiseptic in the form of a tablet.

In a small number of cases, the cause of recurrent UTIs is not identified. In these cases, your doctor may prescribe cystistat. 

Cystistat is a liquid medication applied to the inner lining of the bladder by a nurse using a catheter. It is given once a week for  4–6 weeks. When given, you will be asked to turn around while lying down to ensure it coats all the inner surfaces of your bladder. 

Cystistat is used to treat painful bladder syndrome and recurrent UTIs. It works by temporarily replacing the protective inner lining of the bladder, which has been damaged.

How to reduce your risk of UTIs

You can reduce your risk of UTIs with a few, simple lifestyle changes. Make sure you: 

• Empty your bladder after sex
• Empty your bladder when you have the urge
• Follow a diet rich in fresh fruits and vegetables and fibre to avoid constipation
• Stay hydrated

You can also drink cranberry juice or take cranberry or D-mannose capsules. Cranberries contain a substance called A-type proanthocyanidins, which helps prevent bacteria from sticking to the inner lining of the bladder. D-mannose works in a similar way, making it easier for bacteria to be washed out of the bladder when urinating. 

If you are post-menospausal, you can boost oestrogen levels locally in your vagina and urethra to counteract the changes that increase your UTI risk. This involves inserting oestrogen pessaries into your vagina. 

If you have a prolapse, daily pelvic floor exercises can help improve prolapse symptoms and reduce your risk of UTIs.