My urine is really dark: what should I know?

Urine may look darker first thing in the morning, after sweating, vomiting or diarrhoea, or when you have had little fluid. A change after a food, vitamin or medicine can also alter its colour. The shade, how long it lasts, and any other symptoms help guide the next step.

Deep yellow urine commonly occurs when it is more concentrated. Clearer urine after drinking fluids may support dehydration as an explanation, although colour alone cannot confirm the cause.

Brown, tea-coloured or cola-coloured urine can occur when bile pigments enter the urine, including with liver inflammation such as hepatitis. It can also reflect blood or muscle breakdown, so a new unusual colour deserves attention, particularly if it does not settle.

Pain or burning when passing urine, a strong urge to urinate, fever, or pain in the side can point to a urinary problem. Yellowing of the skin or eyes, pale stools, nausea, or marked tiredness makes liver-related illness more concerning.

If you feel well and the urine became darker after heat, exercise or low fluid intake, drink fluids regularly and check whether the colour becomes lighter over the next several hours. Replace fluids gradually if you have been sweating or losing fluid.

Think about recent foods, supplements and medicines, and note the colour without relying on a photo taken under unusual lighting. Do not stop a prescribed medicine without checking with a clinician or pharmacist.

Arrange a medical review if dark urine persists, keeps returning, or has no clear explanation. A clinician may ask about fluid loss, medicines and other symptoms, examine you, and test a urine sample or blood if needed.

Seek urgent medical help if dark urine comes with confusion, fainting, severe weakness, inability to keep fluids down, very little urine, or signs of serious heat illness such as a very high body temperature.

Get prompt medical advice for blood-coloured or cola-coloured urine, severe side or abdominal pain, fever with urinary symptoms, yellow skin or eyes, or new pale stools. These features can signal a problem that should not be assessed by colour alone.

Ask whether the colour could be related to dehydration, a medicine or supplement, a urinary infection, blood, or liver irritation. Tell them when it began, whether it changes after fluids, and whether you have pain, fever, vomiting, yellowing, or reduced urine.