What should you know about extremely dark brown urine?

Urine may become dark brown when it is concentrated after sweating, vomiting, diarrhoea or limited fluid intake. Heat exhaustion can involve heavy sweating, weakness, headache, dizziness and nausea. Brown urine with yellowing of the eyes or skin, pale stools, itching, nausea or abdominal discomfort may occur with hepatitis A or hepatitis B. Blood or muscle pigment can also alter urine colour. Food and medicines can change urine appearance, but a striking change that does not clear should not be dismissed.

Move to a cool place if heat exposure is involved, rest, and take regular fluids if you are alert and able to drink. Note recent exercise, foods, medicines, fluid loss and the time the colour changed. Arrange medical review if the urine remains brown, returns repeatedly, or occurs with pain, fever, jaundice, vomiting or reduced urination. A urine and blood assessment may be needed.

Seek urgent care for dark brown urine with confusion, fainting, severe weakness, inability to keep fluids down, very little urine, severe abdominal or side pain, or yellow skin and eyes. After intense heat or exertion, these symptoms may signal significant fluid loss or another condition needing immediate treatment.

Ask whether you need urine testing, liver and kidney checks, or a review of your medicines. Tell the clinician about recent travel, possible hepatitis exposure, heat, strenuous activity, fluid loss, pain and changes in stool colour.