What should you know about really dark urine in morning?

Several hours without drinking can make the first urine darker than later samples. Overnight sweating, a warm room, alcohol, vomiting or diarrhoea can increase fluid loss and make the change more pronounced; see Dehydration for related signs. If urine lightens during the day and you feel well, concentration may explain it. If it remains brown or orange, or appears with yellow eyes, pale stools, itching, pain or weakness, other causes such as medicines, bile pigments or muscle injury need consideration. Hepatitis A and Hepatitis B can involve dark urine, but this symptom alone does not diagnose them.

Note the first-morning colour, then observe whether it changes later after your usual fluids. Record urine amount, sleep conditions, recent heat, illness, exercise, foods, supplements and medicines. Do not wake yourself repeatedly to drink or force excessive water. Arrange a medical review when dark urine lasts through the day, returns often, or occurs with other symptoms. A urine sample can be useful if requested.

Seek urgent help for no or very little urine, confusion, fainting, severe weakness, severe abdominal or back pain, repeated vomiting, or muscle pain with dark urine after strenuous activity. Get prompt review for yellowing of the skin or eyes, pale stools, swelling, easy bruising or persistent dark colour. Heat exposure followed by dizziness, weakness or illness may indicate Heat Exhaustion and should not be ignored.

Ask whether the morning-only pattern fits concentration, whether your medicines or supplements can alter urine, and whether urine or blood tests are needed. Ask which symptoms should prompt urgent care.