Blood in urine test: what to know

A dipstick can screen for haemoglobin or myoglobin, while microscopy looks for red blood cells and other features. A positive dipstick does not by itself identify the cause: exercise, infection, stones, menstrual or vaginal contamination, muscle breakdown and some medicines can affect the result. A culture may look for bacteria when infection is suspected. The amount seen on one sample does not tell you how serious the cause is, and a normal-looking urine sample does not always exclude microscopic blood.

Follow the collection instructions and provide a clean midstream sample when requested. Tell the clinician about menstruation or vaginal bleeding, recent exercise, injuries, urinary symptoms, medicines and previous results. Do not stop prescribed treatment without advice. If infection is found, treatment and a repeat sample may be recommended. Persistent or unexplained blood can lead to additional checks of the kidneys, ureters or bladder, based on your symptoms and medical history.

Get urgent help for inability to pass urine, clots, heavy visible bleeding, severe flank pain, fever with chills, fainting, confusion or repeated vomiting. A small or painless test abnormality may not be an emergency, but it still deserves the follow-up your clinician recommends. Return promptly if blood appears again after an initially reassuring result.

Was the result from a dipstick, microscopy or culture? Were red blood cells actually seen? Could contamination or recent exercise explain it? Do I need a repeat sample, imaging or specialist review? Which warning signs should prompt urgent care?