What are the first signs of food poisoning?

Food poisoning is an illness caused by contaminated food or drink. Early symptoms can include [Nausea](/symptoms/nausea/), abdominal cramps, loose stools, [Vomiting](/symptoms/vomiting/), and [Fever](/symptoms/fever/). Some people also feel weak or develop headache. Symptoms may start after a short delay, and people who ate the same food may become unwell at different times.

A similar illness can occur during travel, including [Traveller's Diarrhoea](/conditions/travellers-diarrhoea/). The symptom pattern alone cannot identify the germ or prove which meal caused it.

Take frequent small sips of water or an oral rehydration drink. If vomiting settles, gradually try plain foods and continue drinking. Rest, wash hands carefully, and avoid preparing food for others while you have diarrhoea or vomiting.

Monitor urine, thirst, dizziness, and energy levels. Avoid alcohol and very rich foods until your stomach improves. A clinician can advise whether testing or treatment is needed; severe dehydration may require [IV Fluid Therapy](/treatments/acute-and-urgent-care/iv-fluid-therapy/).

Get urgent medical help for blood in the stool or vomit, severe or worsening [Abdominal Pain](/symptoms/abdominal-pain/), confusion, fainting, breathing difficulty, or inability to keep fluids down. Seek prompt advice if you are passing very little urine, feel markedly dizzy, or have a fever with severe illness.

Could this be food poisoning or another infection? How should I replace fluids? Do I need an examination or stool testing, and when is it safe to return to work, school, or food preparation?