Dark brown urine and dehydration

When the body has less fluid available, the kidneys conserve water and urine becomes more concentrated, often darker and stronger-smelling. This can follow diarrhoea, vomiting, fever, heavy sweating, heat exhaustion, or simply drinking too little. Gastroenteritis is a common setting for fluid loss. Dark urine may have another explanation if it is tea-coloured despite adequate fluids, or if it comes with burning, pain, cloudy urine, or blood.

Take frequent small drinks and follow medical advice about oral rehydration if diarrhoea or vomiting is present. Rest somewhere cool after heat exposure. Keep track of whether you are urinating and whether the colour is becoming lighter. People with kidney, heart, or liver disease may need a personalised fluid plan, so they should check before increasing intake substantially. Do not use urine colour alone to judge recovery.

Seek urgent care for confusion, fainting, severe weakness, inability to keep fluids down, no urine, severe abdominal or side pain, or blood in urine. Fever with painful urination can occur with a urinary tract infection. Waves of severe side pain may point to kidney stones. Dark urine with yellow eyes or skin needs prompt assessment for a liver or bile-related problem.

Ask how much and what type of fluid suits your illness, whether you need electrolyte replacement, how to recognise worsening dehydration, and whether urine testing is needed if the colour remains dark.