Causes of dark urine in the morning

Deep yellow or amber urine that becomes lighter after drinking is commonly linked with overnight fluid loss. Warm weather, sweating, vomiting, or diarrhoea can make concentration more marked; dehydration and heat exhaustion are relevant possibilities. Food dyes and some medicines can also alter colour. Tea-coloured or brown urine, especially with yellowing of the eyes, pale stools, nausea, or discomfort, can occur with liver problems such as hepatitis A or hepatitis B. Pink, red, or cola-coloured urine may contain blood or pigment from muscle breakdown and should be assessed rather than explained by morning concentration alone.

Notice the shade, smell, amount, and whether it returns to a lighter colour after normal drinking. Sip fluids regularly unless a clinician has told you to restrict them. Review recent exercise, heat exposure, stomach illness, supplements, and medicines. Do not stop a prescribed medicine without advice. A clinician may ask for a urine sample and blood tests if the change persists or if you have pain, fever, swelling, or changes in bowel or eye colour.

Arrange prompt medical advice for dark urine that continues through the day, recurs over several mornings, or appears with burning, flank pain, fever, vomiting, or reduced urination. Seek urgent help for confusion, fainting, severe weakness, inability to keep fluids down, marked yellowing, or very little urine. These warning signs can indicate significant fluid loss or a problem needing examination.

Could my medicines, supplements, or recent illness explain the colour? Do I need urine testing for blood or infection? Should my liver or kidney function be checked? What fluid plan is suitable for me?