Waking up with dark urine: what to know

Urine is often darker after several hours without drinking, especially after sweating, fever, vomiting, or diarrhoea. It should generally become lighter as you drink normally and pass urine through the day. Food, supplements, and some medicines can also alter colour.

Dark urine that continues may occur with blood, muscle breakdown, or liver and bile-flow problems. Hepatitis A and [Hepatitis B](/conditions/hepatitis-b/) can be associated with dark urine, often alongside yellowing of the eyes or skin, pale stools, nausea, or unusual tiredness. The colour alone cannot identify the cause.

Note the colour, smell, frequency, and whether there is pain or burning. Drink fluids steadily if you can do so safely, and observe whether the urine lightens. Do not force large amounts of fluid if a clinician has given you a fluid restriction.

Arrange medical advice if the change persists, returns without an obvious reason, or comes with fever, back or side pain, burning, or reduced urine. Consider [Dehydration](/conditions/dehydration/) or [Heat Exhaustion](/conditions/heat-exhaustion/) if fluid loss followed heat or heavy sweating, but do not assume either diagnosis.

Seek urgent care for very little or no urine, severe weakness, confusion, fainting, severe abdominal or side pain, or repeated vomiting. Red or cola-coloured urine, yellow skin or eyes with worsening illness, or dark urine after intense muscle pain also warrants prompt assessment.

Ask whether you need a urine test, blood tests, or imaging. Tell the clinician when the colour began, what you drank, recent exercise or heat exposure, medicines and supplements, and whether you have pain, fever, jaundice, or urinary changes.