Blood in the urine (haematuria): a case-based approach

The case: noticing red urine

Meet "David", a fictional 62-year-old retired teacher. One morning he passes urine that is clearly pink-red, with no pain and no fever. It happens once, then his urine looks normal again the next day. Because it did not hurt and quickly settled, David is tempted to ignore it. This is exactly the trap doctors worry about. Painless visible blood in the urine in an adult is a classic warning sign that must be investigated, because bladder and kidney cancers often bleed intermittently and without pain. The fact that it stopped does not mean the cause has gone away. David sensibly books a GP appointment, which is the right first step.

Visible versus non-visible blood

Doctors divide haematuria into two types. Visible (or "frank") haematuria is blood you can see, turning the urine pink, red or brown. Non-visible haematuria is blood found only on a urine dipstick or microscope test, often picked up during an unrelated check. Both types can matter, but visible blood carries a higher risk of serious disease and prompts faster investigation. Common causes range from urine infections and kidney stones to an enlarged prostate, vigorous exercise, and, importantly, cancers of the bladder, kidney or prostate. In women, it is important not to confuse menstrual blood with true haematuria. Whatever the suspected cause, the golden rule is simple: visible blood in the urine always needs to be checked.

The GP assessment and urgent referral

David's GP asks about smoking (a major risk factor for bladder cancer), any pain, urinary symptoms, recent infections, and medicines that thin the blood. They examine him, check his blood pressure, test his urine to look for infection, and take blood tests including kidney function. Because David has painless visible haematuria and is over 45, NICE guidance means he should be referred urgently on a suspected-cancer pathway, aiming to be seen within two weeks. Being referred on this pathway does not mean he has cancer — most people investigated do not — but it ensures serious causes are ruled out quickly. Finding a urine infection does not remove the need to investigate visible blood in an older adult.

Tests in the hospital clinic

At the clinic, David meets a urology team. The key test for the bladder is a cystoscopy, where a thin flexible camera is passed into the bladder through the water pipe after numbing gel, allowing the lining to be inspected directly. He also has imaging of his kidneys and urinary tract, often a CT scan or ultrasound, to look for stones, tumours or other abnormalities. Further urine tests may be sent. The combination of camera and scan covers the whole urinary system from kidney to bladder. If everything is clear, David will be reassured and told what to watch for; if something is found, it can be treated early. Early investigation gives the best chance of a good outcome.

When blood in the urine is an emergency

Most haematuria is investigated calmly through GP and clinic appointments, but some situations need urgent care. Seek emergency help if you are passing large amounts of blood or clots, cannot pass urine at all, or feel faint, breathless or very unwell. Call 999 or go to A&E if bleeding is heavy and you feel dizzy, have a racing heart, or collapse, as heavy blood loss can be dangerous. Severe one-sided back or side pain with blood may suggest a kidney stone and needs same-day assessment. This article is for education only and cannot diagnose you. Remember the key message: any visible blood in your urine, even once and even painless, should always be checked by a doctor — if you are severely unwell, call 999.