What should you know about consistent dark urine?

Urine can look darker when it is concentrated, especially after sweating, vomiting, diarrhoea, fever, or drinking less than usual. Heat exhaustion may occur with heavy sweating, weakness, headache, dizziness, nausea, or cramps. Food, supplements, and some medicines can also change urine colour. Tea-coloured or brown urine, particularly with yellowing of the eyes or skin, pale stools, itching, nausea, or pain, can occur with liver inflammation such as hepatitis A or hepatitis B. Red, pink, or cola-coloured urine may also represent blood or pigment from muscle injury and needs medical review.

Consider the colour in good lighting and note whether it changes after normal fluid intake. The colour alone cannot identify the cause.

If you have no fluid restriction, take regular small drinks and avoid excessive heat and strenuous activity while you monitor the change. Review any newly started medicines, vitamins, or supplements, but do not stop prescribed treatment without advice. Arrange a medical appointment when dark urine continues, returns repeatedly, or is accompanied by burning, frequent urination, abdominal pain, fever, unusual tiredness, or changes in bowel movements. A clinician may ask for a urine sample and blood tests to clarify the cause.

Seek urgent help for confusion, fainting, severe weakness, inability to keep fluids down, very little urine, severe abdominal or back pain, or signs of serious heat illness. Get prompt medical assessment for yellow skin or eyes, fever with pain when urinating, visible blood, or dark urine after significant muscle injury. If you have liver disease, are pregnant, or take medicines that affect the liver or kidneys, contact a clinician sooner.

Ask whether dehydration, a medicine or supplement, infection, liver inflammation, or blood in the urine could explain the change; ask which tests are appropriate and which symptoms require same-day help.