What Does Dark-Coloured Urine Indicate?

Dark-coloured urine often reflects concentrated urine, but it can also signal bleeding, liver or bile problems, infection, or muscle breakdown. The shade and accompanying symptoms help guide the next step. Urine that becomes darker after sweating, vomiting, diarrhoea, or not drinking enough may improve as hydration returns. Persistent dark urine, cola-coloured urine, or urine with pain, fever, yellow skin, or reduced urine output deserves medical advice.

Deep yellow or amber urine commonly occurs when it is concentrated. Dehydration can happen with heat, exercise, fever, vomiting, or diarrhoea; heat exhaustion may add heavy sweating, weakness, dizziness, headache, or nausea. Brown or tea-coloured urine can occur when bile pigments enter the urine during a liver or bile-flow problem, sometimes alongside yellow eyes, pale stools, itching, nausea, or discomfort beneath the right ribs. Pink, red, or smoky urine may contain blood, while very dark urine after strenuous activity with marked muscle pain or weakness can reflect muscle injury. Some foods, vitamins, and medicines can also change urine colour.

Notice when the change began, how the colour looks in good light, and whether it follows heat, exercise, illness, a new medicine, or a particular food. If you feel well and dehydration seems plausible, take regular drinks and monitor whether the urine lightens. Do not force large amounts of fluid if you have been told to restrict fluids or have kidney, heart, or liver disease. Do not stop a prescribed medicine without advice. A clinician may check a urine sample, hydration, blood counts, kidney function, liver tests, or muscle enzymes depending on the history.

Seek urgent medical care for dark urine with confusion, fainting, severe weakness, inability to keep fluids down, very little urine, severe abdominal or back pain, or rapidly worsening illness. Arrange prompt assessment if you see blood or clots, have burning urination with fever or flank pain, develop yellow skin or eyes, or notice tea- or cola-coloured urine after intense exercise or an injury. Contact a clinician if the colour stays dark despite drinking normally, keeps returning, or has no clear explanation.

You could ask: Could this colour be caused by dehydration, blood, a medicine, or a liver problem? Which urine or blood tests are appropriate? Should I change my fluid intake given my existing conditions? What symptoms should prompt urgent care? Bring a list of medicines and supplements, recent illnesses, exercise or heat exposure, and any change in bowel movements or skin colour.