What should you know about urine turns dark on standing?

A stored sample may become more concentrated or show settled pigments, making it appear deeper in colour. Dark urine in a fresh sample can occur when you have not replaced fluid lost through heat, sweating, vomiting, or diarrhoea. [Dehydration](/conditions/dehydration/) and [Heat Exhaustion](/conditions/heat-exhaustion/) may also cause thirst, dizziness, weakness, headache, or reduced urination. Tea-coloured urine with yellowing of the eyes or skin, pale stools, nausea, or upper abdominal discomfort needs assessment for liver-related illness, including [Hepatitis A](/conditions/hepatitis-a/) or [Hepatitis B](/conditions/hepatitis-b/).

Compare the colour of a fresh sample in a clean container and note whether it changes after drinking normally. Move to a cool place after heat exposure and take small, regular sips if you can drink safely. Do not force fluids if a clinician has restricted them. Record medicines, supplements, recent exercise, fever, and any change in bowel movements or skin colour for your appointment.

Seek urgent help for confusion, fainting, inability to keep fluids down, very little urine, severe weakness, or suspected heat illness. Arrange prompt medical review for dark urine that remains dark when fresh, especially with yellow skin or eyes, abdominal pain, fever, pale stools, or worsening fatigue.

Ask whether your fresh urine needs testing and whether medicines, supplements, fluid loss, or liver symptoms could explain the colour. Mention when the change began and whether it occurs after standing only or in every sample.