What should you know about black blood in urine?

Urine may look brown, cola-coloured, or nearly black when blood has been altered as it travels through the urinary tract, or when the urine is very concentrated. Food, medicines, muscle breakdown, and liver or kidney problems can also change urine colour, so appearance alone cannot identify the cause.

Possible urinary causes include a urinary tract infection, kidney infection, kidney stones, prostate inflammation, or an enlarged prostate. Less commonly, bleeding can be linked with bladder, kidney, or prostate cancer. These conditions can present with blood in urine; the colour does not show which one is responsible.

Arrange an urgent clinical assessment rather than waiting for the colour to settle. A clinician may ask when it began, whether the urine contains clots, and whether you have burning, pain, fever, or recent injury. Testing can include a urine sample, blood tests, and imaging when appropriate.

Do not stop a prescribed medicine without advice, but make a list of every medicine and supplement you take. Drink your usual fluids unless a clinician has told you to restrict them, and note a sample or photograph of the colour if it changes before you are seen.

Seek emergency care now if you cannot pass urine, are passing large clots, have severe side or lower abdominal pain, feel faint or confused, or have heavy ongoing bleeding. Fever with chills, vomiting, or pain in the back or flank can signal an infection that needs rapid treatment.

Ask whether the urine needs testing for blood and infection, whether imaging is needed, and which symptoms should bring you back urgently. Mention any urinary symptoms, recent exercise or injury, period-related bleeding, and family history of urinary disease.