What causes food poisoning?

Food poisoning is caused by germs or toxins entering food or drink and then irritating or infecting the digestive system. Bacteria, viruses, parasites, and pre-formed toxins are possible causes. The illness may begin after a short delay or take longer, depending on the organism and the amount consumed.

Food can become unsafe when raw meat or eggs touch cooked food, when hands or utensils are not washed, or when food is left at temperatures that allow germs to multiply. Unpasteurised products, unsafe water, poorly washed produce, and undercooked seafood are other routes. Abdominal pain, diarrhoea, nausea, vomiting, and fever may follow, but these symptoms do not identify one cause by themselves.

Replace lost fluid with frequent sips of water or Oral Rehydration Therapy. Resume simple foods as tolerated and rest. Wash hands carefully after using the toilet and before handling meals; clean shared bathroom surfaces. Do not prepare food for other people while you have vomiting or diarrhoea. A clinician can decide whether testing or treatment is appropriate based on severity and health history.

Arrange urgent assessment for bloody diarrhoea, severe abdominal pain, persistent vomiting, faintness, confusion, signs of dehydration, or a fever with significant weakness. Get advice sooner for a young child, an older adult, pregnancy, or reduced immunity. These groups may lose fluid rapidly or need a lower threshold for assessment.

Ask what cause is most consistent with the timing and symptoms, whether a stool sample is useful, and which drinks or medicines are suitable. Mention recent travel, restaurant meals, new medicines, and whether other people shared the same food.