Dark urine after food poisoning: what to know

Food poisoning can cause vomiting, diarrhoea, fever and poor intake. Losing water and salts makes urine more concentrated, so it may look amber and smell stronger. Dark urine with dizziness, dry mouth, unusual tiredness or reduced urination suggests dehydration is becoming more significant. Tea-coloured or brown urine, blood, severe abdominal pain or yellow eyes should not be attributed to food poisoning without an examination. The illness may have settled while dehydration continues.

Take small, frequent sips rather than drinking a large amount at once. Oral rehydration therapy can replace water and salts lost through vomiting or diarrhoea; follow the product instructions. Once tolerated, resume light foods and continue monitoring urine and alertness. A clinician may recommend IV fluid therapy when drinking is not possible or fluid loss is substantial. Avoid self-treating severe symptoms with leftover medicines. Keep a note of stools, vomiting, fever, urine output and any blood.

Get urgent help for fainting, confusion, severe weakness, very little urine, inability to keep fluids down, blood in vomit or stool, severe abdominal pain, or a high fever with a very unwell appearance. Seek prompt advice if dark urine continues after vomiting and diarrhoea improve, or if it is brown, red or accompanied by yellow skin or eyes. Children, older adults and people with chronic illness may need earlier review.

Ask whether oral rehydration is suitable, how to recognise inadequate replacement, and whether you need urine or blood tests. Ask when IV fluid therapy is considered and which medicines to avoid while dehydrated.