What should you know about dark urine and blood?

Concentrated urine can look deep yellow or amber after fluid loss, including from sweating, vomiting, diarrhoea, or not drinking enough. Blood may make urine pink, red, or brown, although a small amount is not always obvious. Bleeding can arise anywhere along the urinary tract, including the kidneys, bladder, or urethra. A urinary infection may bring burning, urgency, or an unusual smell; a stone may cause strong side or groin pain. Foods and medicines can also alter urine colour, so appearance alone cannot identify the cause.

Note when the change began, whether it happens every time you pass urine, and whether you can see clots. Drink fluids normally unless a clinician has told you to restrict them, and avoid strenuous activity until the cause is clearer. Arrange a medical assessment, especially if blood is visible, the change persists, or you have pain, fever, or urinary symptoms. A clinician may check a urine sample and decide whether blood tests or imaging are appropriate.

Seek urgent medical help for heavy bleeding, clots that interfere with passing urine, inability to urinate, severe side or abdominal pain, fever with chills, faintness, confusion, or repeated vomiting. These symptoms can signal significant bleeding, infection, obstruction, or dehydration and should not be watched at home.

Ask whether the urine needs testing for blood or infection, whether any medicines or supplements could explain the colour, and which changes should prompt immediate review. Mention recent exercise, illness, injuries, menstrual bleeding, and any history of urinary problems.