Urinary tract infections (UTIs) rank among the most common bacterial infections worldwide, affecting an estimated 150 million people annually 1. If you’ve ever experienced that burning sensation when urinating or felt the urgent need to go every few minutes, you’re not alone. Women bear the brunt of this burden, with roughly half experiencing at least one UTI during their lifetime.

This guide covers everything you need to know about UTIs, from understanding why they happen to recognising the warning signs and knowing when home care is enough versus when you should see a doctor.

What Exactly Is a UTI?

A UTI occurs when bacteria, most commonly Escherichia coli (E. coli) from the gut, enter the urinary tract and multiply. Your urinary tract includes:

Kidneys - filter waste from your blood to produce urine
Ureters - thin tubes carrying urine from kidneys to bladder
Bladder - stores urine until you’re ready to urinate
Urethra - the tube through which urine exits your body

The infection can develop in any part of this system, though the bladder (causing cystitis) and urethra (causing urethritis) are the most commonly affected. When bacteria travel up to the kidneys, the resulting infection (pyelonephritis) becomes considerably more serious.

Who Gets UTIs and Why?

Women are far more likely to develop UTIs than men, primarily because of anatomy. A woman’s urethra is shorter and located closer to the rectum, making it easier for bacteria to reach the bladder. Some estimates suggest women are up to 30 times more likely to develop a UTI 2.

Several factors increase your risk:

Biological and anatomical factors:

Being female (shorter urethra, proximity to rectum)
Pregnancy (hormonal changes alter urinary tract)
Menopause (reduced oestrogen affects protective vaginal flora)
Previous UTIs (having one increases risk of another)
Urinary tract abnormalities present from birth

Behavioural factors:

Sexual activity (can introduce bacteria into the urethra)
Using diaphragms or spermicides for contraception
Poor toilet hygiene (wiping back to front)
Not urinating frequently enough

Medical factors:

Diabetes (high blood sugar feeds bacteria)
Kidney stones or other obstructions
Urinary catheter use
Weakened immune system
Benign prostatic hyperplasia in men
Urinary retention from any cause

If you’re experiencing frequent infections, understanding your personal risk factors can help you and your doctor develop a targeted prevention strategy. We have a dedicated article on recurrent UTIs that goes into more depth on this topic.

Recognising UTI Symptoms

The symptoms you experience depend largely on which part of the urinary tract is infected.

Lower UTI Symptoms (Bladder Infection)

Most UTIs start in the lower urinary tract and produce these classic symptoms:

Burning or stinging sensation when urinating (dysuria)
Needing to urinate urgently and frequently
Passing small amounts of urine despite feeling desperate to go
Urine that looks cloudy, dark, or has blood in it
Strong or unpleasant-smelling urine
Pain or pressure in your lower abdomen or pelvis
Generally feeling unwell

Upper UTI Symptoms (Kidney Infection)

When infection reaches the kidneys, symptoms become more severe:

High temperature (fever above 38°C)
Shivering and chills
Pain in your back or side, typically below the ribs
Nausea and vomiting
Confusion (particularly in elderly patients)

I can’t stress this enough: kidney infections require prompt medical attention. Left untreated, the bacteria can enter the bloodstream (sepsis), which is a medical emergency. If you develop high fever, severe back pain, or feel extremely unwell, see a doctor the same day or go to A&E.

How UTIs Are Diagnosed

Diagnosis usually involves a straightforward urine test. Your doctor or pharmacist may use a dipstick test that changes colour to indicate the presence of bacteria, white blood cells, or blood. This takes just a few minutes and can be done at a GP surgery or pharmacy.

For recurrent infections or complicated cases, your doctor might send a urine sample to a laboratory for culture. This identifies exactly which bacteria are causing the infection and which antibiotics will be most effective, which typically takes two to three days.

Additional tests may be needed if:

You have recurrent UTIs (more than three per year)
Your infection doesn’t respond to initial treatment
There’s concern about structural abnormalities

These might include ultrasound imaging, CT scans, or cystoscopy (where a thin camera is inserted into the bladder to look directly at the urinary tract).

Treatment Options

Antibiotics: The Standard Approach

Most UTIs clear up within a few days of starting antibiotics. The NHS recommends a short course of three to five days for uncomplicated infections in women 2. Men and people with complicated infections may need longer courses.

Commonly prescribed antibiotics include:

Nitrofurantoin (Macrobid) - Often the first choice for uncomplicated UTIs. It concentrates well in urine and has low resistance rates. Take it with food to reduce stomach upset. Not suitable if you have poor kidney function.

Trimethoprim - A single agent that’s effective against most UTI-causing bacteria. Resistance has increased in some areas, so your doctor may check local resistance patterns.

Fosfomycin (Monurol) - Given as a single dose, which makes it convenient. Particularly useful when other options aren’t suitable or resistance is a concern.

Trimethoprim-sulfamethoxazole (co-trimoxazole) - A combination antibiotic that’s effective but has more potential side effects and drug interactions.

Complete your entire antibiotic course even if you feel better after a day or two. Stopping early risks the infection returning and contributes to antibiotic resistance, which is a growing global health concern.

Managing Symptoms at Home

While waiting for antibiotics to work, or alongside treatment:

Drink plenty of water to help flush bacteria from your system
Paracetamol can help with pain and fever
A hot water bottle on your tummy or between your thighs may ease discomfort
Avoid alcohol and caffeine, which can irritate the bladder

Some people find relief with over-the-counter sachets containing sodium citrate or potassium citrate, which make urine less acidic and can reduce burning. However, these don’t treat the infection itself.

When Antibiotics Don’t Work

If your symptoms don’t improve within 48 hours, or if they worsen, contact your doctor. You may have:

A resistant bacteria requiring a different antibiotic
A complicated infection needing longer treatment
Another condition mimicking UTI symptoms

The rise of antibiotic-resistant bacteria, particularly extended-spectrum beta-lactamase (ESBL) producing E. coli, means culture-guided treatment is increasingly important 3.

Preventing UTIs

Prevention is better than cure, particularly if you’re prone to recurrent infections. Some evidence-backed strategies:

Hydration and Toilet Habits

Drink plenty of fluids throughout the day
Don’t hold on when you need to urinate
Urinate soon after sexual activity
Wipe from front to back after using the toilet
Avoid constipation (straining can affect bladder emptying)

Contraception Choices

If you use a diaphragm or spermicide and get frequent UTIs, discuss alternatives with your doctor. These products can alter vaginal flora and increase UTI risk.

Supplements and Natural Approaches

Cranberry products - The evidence here is mixed. A 2023 Cochrane review found cranberry products may reduce UTI risk in some groups, particularly women with recurrent infections 4. They’re unlikely to help treat an active infection, though. If you want to try cranberry, capsules or tablets with standardised proanthocyanidin content are probably more practical than drinking litres of juice.

D-mannose - This simple sugar may prevent E. coli from sticking to bladder walls. Some studies show promise, but more research is needed. It’s generally safe if you want to try it.

Probiotics - Specifically, lactobacillus strains that help maintain healthy vaginal flora. Evidence is emerging but not yet conclusive.

Medical Prevention for Recurrent UTIs

For people with frequent infections (typically defined as three or more per year), doctors may recommend:

Low-dose preventive antibiotics - taken daily or after sexual activity
Vaginal oestrogen - for postmenopausal women, helps restore protective vaginal flora
Self-start antibiotics - having a prescription ready to use at the first sign of infection

Special Considerations

UTIs in Pregnancy

Pregnant women are more susceptible to UTIs and face higher risks if infections aren’t treated, including preterm labour and low birth weight babies. Screening for bacteria in urine is routine during antenatal care, even in women without symptoms. Some antibiotics are safer than others during pregnancy, so always tell your doctor or pharmacist if you’re pregnant or might be.

UTIs in Older Adults

UTI symptoms can be atypical in elderly people. Confusion or sudden changes in behaviour may be the only sign, particularly in people with dementia. However, it’s worth noting that many older adults have bacteria in their urine without any infection (asymptomatic bacteriuria), and treating this unnecessarily does more harm than good.

UTIs in Men

While less common than in women, UTIs in men warrant thorough investigation. They often indicate an underlying problem such as prostate enlargement or bladder dysfunction. Men with UTI symptoms should always see a doctor rather than self-treating.

Children and UTIs

UTIs in children can be serious and may indicate structural abnormalities in the urinary tract. Symptoms to watch for include fever without obvious cause, unusual-smelling urine, bed-wetting in previously dry children, and irritability or poor feeding in babies. Always seek medical advice for suspected UTI in children.

When to Seek Medical Help

See a doctor if:

This is your first UTI
You’re pregnant
You’re a man with UTI symptoms
Symptoms don’t improve within two days of starting treatment
You have blood in your urine that’s visible to the naked eye
You have fever, chills, or back pain (suggesting kidney involvement)
You have diabetes, kidney disease, or a weakened immune system
You’re over 65

Go to A&E or call emergency services if:

You have severe pain that painkillers don’t control
You’re unable to urinate at all
You’re confused, very drowsy, or have a racing heart
You have a very high fever with shaking chills

Key Takeaways

UTIs are common, treatable infections that most people recover from quickly with appropriate antibiotics. The burning sensation and constant urge to urinate are unpleasant but usually resolve within a few days of treatment. Prevention strategies, from simple hydration to cranberry supplements, can help reduce recurrence in susceptible individuals.

The important thing is recognising when a simple bladder infection might be becoming something more serious. High fever, back pain, and feeling extremely unwell are red flags that warrant immediate medical attention. For routine UTIs, your GP or even a pharmacist can often help get you sorted quickly.

If you’re dealing with frequent UTIs, don’t just accept them as inevitable. Work with your healthcare provider to identify risk factors and develop a prevention plan tailored to your situation.

References

Flores-Mireles AL, et al. Urinary tract infections: epidemiology, mechanisms of infection and treatment options. Nat Rev Microbiol. 2015;13(5):269-84.
NHS. Urinary tract infections (UTIs). 2022.
Terlizzi ME, et al. UroPathogenic Escherichia coli (UPEC) Infections: Virulence Factors, Bladder Responses, Antibiotic, and Non-antibiotic Antimicrobial Strategies. Front Microbiol. 2017;8:1566.
Williams G, et al. Cranberries for preventing urinary tract infections. Cochrane Database Syst Rev. 2023.