Urinary tract infections are one of the most common reasons women seek treatment in the UK, and for most people a lower UTI is uncomfortable but straightforward to treat. Knowing which symptoms point to a simple bladder infection, when self-care is reasonable, and when you need a clinician can save a lot of worry — and help you avoid antibiotics you do not need.

What a UTI is and the symptoms to look for

A urinary tract infection happens when bacteria — most often from the bowel — enter the urinary system and multiply. When the infection stays in the bladder and urethra it is called a lower UTI, often described as cystitis. Women get UTIs far more often than men because the urethra is shorter, giving bacteria a shorter route to the bladder.

Typical symptoms of a lower UTI include a burning or stinging feeling when you pass urine, needing to go more often or more urgently, passing only small amounts, cloudy or strong-smelling urine, and a dragging discomfort low in the abdomen. Some people notice a trace of blood, and older adults may instead become more confused or generally unwell. Symptoms usually come on over a day or two.

Several things make a UTI more likely. Sexual activity can move bacteria towards the urethra; the drop in oestrogen after the menopause changes the vaginal and urinary tissues; and pregnancy alters the urinary tract. Conditions such as diabetes, or anything that stops the bladder emptying fully, can also raise the risk, and a urinary catheter is another common route for infection. None of this means you have done anything wrong — UTIs are extremely common.

Not every episode of urinary discomfort is an infection. Irritation, dehydration and other conditions can feel similar, which is one reason a clinician may review your symptoms carefully before deciding on treatment.

How a UTI is diagnosed

In a woman with clear, typical symptoms, treatment is often started on the symptoms alone. Where the picture is less certain, a clinician may use a urine dipstick test, or send a sample to the laboratory to confirm which bacteria are involved and which antibiotics they respond to. A laboratory sample is especially useful if a first treatment has not worked, if you are pregnant, or if the infection is more complicated. Understanding this is reassuring: treatment is matched to your situation rather than applied as a one-size-fits-all.

Self-care and when antibiotics are needed

For mild, uncomplicated symptoms, self-care is a reasonable first step while your body clears the infection. Drinking enough fluid, resting, and using paracetamol or ibuprofen for discomfort can all help, and a proportion of simple lower UTIs settle without antibiotics. UK guidance — NICE NG109 sets the framework for managing lower UTIs in primary care — supports offering pain relief and, in some situations, a short delay before antibiotics to see whether symptoms improve on their own.

Over-the-counter cystitis sachets that make the urine less acidic are sometimes used for symptom relief, though the evidence that they change the course of the infection is limited, and they are not suitable for everyone — for example if you have heart or kidney problems, or high blood pressure. It is worth checking with a pharmacist before using them.

Antibiotics become appropriate when symptoms are more troublesome, are not settling, or when there are reasons not to wait. A clinician weighs your symptom pattern, your history of UTIs, whether you could be pregnant, and your kidney function before recommending a course. Antibiotics are not automatically the right answer for every twinge — using them only when needed helps keep them working for when they matter.

First-line antibiotics in the UK

When antibiotics are indicated for a non-pregnant woman with a lower UTI, the two usual first-line choices are nitrofurantoin and trimethoprim. A typical course is nitrofurantoin 100mg modified-release twice daily for three days, or trimethoprim 200mg twice daily for three days. Three days is usually enough for a simple bladder infection in an otherwise healthy woman.

The choice between them is not arbitrary. Nitrofurantoin is generally avoided when kidney function is reduced (a low eGFR), because it may be less effective and more likely to cause side effects. Trimethoprim is usually avoided if you have taken it recently, or where local bacterial resistance is known to be high, because the infection is less likely to respond. Your clinician will advise based on your individual circumstances, including any allergies and other medicines you take.

Where neither first-line option is suitable, other antibiotics such as fosfomycin may be considered for some patients. Whatever is prescribed, taking the course exactly as directed and getting back in touch if symptoms do not improve within a couple of days is important.

There is a wider reason clinicians are careful with antibiotics. Overusing them drives antibiotic resistance, which the UK monitors closely, so guidance favours short, targeted courses. This is not about withholding treatment — it is about matching the right antibiotic, at the right dose, for the right length of time, to your particular infection.

Recurrent UTIs and prevention

Some women get UTIs repeatedly. Recurrent UTIs are usually defined as two or more infections in six months, or three or more in a year. If that sounds like you, it is worth a fuller review rather than simply treating each episode as it comes.

Everyday measures can help reduce the frequency for some people: staying well hydrated, not holding on when you need to pass urine, and passing urine after sex. Evidence for some traditional remedies is mixed, and no single measure works for everyone. After the menopause, falling oestrogen can thin and dry the vaginal and urinary tissues, which makes some women more prone to UTIs — one situation where options discussed as part of the menopause treatment pathway may be relevant.

For women whose recurrent infections are linked to the menopause, a clinician may discuss vaginal oestrogen, which can help restore the tissues and reduce infections for some people. Other preventive approaches, including longer or standby courses of antibiotics in selected cases, are sometimes considered, but these are individualised decisions that balance the benefit against the downsides of regular antibiotics. Keeping a simple record of when infections happen helps your clinician spot a pattern.

Recurrent urinary symptoms are sometimes confused with vaginal thrush, which causes itching and discharge rather than burning on passing urine. Telling them apart matters, because the treatments are completely different.

Red flags — when a UTI needs urgent review

Certain features mean a UTI should be reviewed by a clinician rather than managed as a simple bladder infection:

  • Fever, shivering, or feeling generally unwell
  • Pain in your back or side (loin or flank pain), which can signal the kidneys are involved
  • Nausea and vomiting
  • Blood in the urine, especially if it persists
  • Symptoms during pregnancy
  • UTI symptoms in men
  • Symptoms that do not improve within 48 hours of starting antibiotics

A UTI in pregnancy, or one that reaches the kidneys (pyelonephritis), needs prompt clinical assessment and sometimes different treatment. UTIs in men are less common and are treated as complicated by default, so they always warrant review. If you feel very unwell, become confused, or cannot keep fluids down, seek urgent medical help.

Working with your Farmeci clinician

An online consultation for cystitis covers your symptoms, how long they have lasted, whether you have had UTIs before, any allergies, other medicines, and whether you could be pregnant. From there, a UK-registered clinician can advise whether antibiotics are appropriate, which option suits you, or whether you should be seen in person. You can read more across our Women's Health articles for related topics.