Fast food poisoning: what to know

Food poisoning is an illness caused by contaminated food or drink. Symptoms may begin soon after eating or later, depending on the cause. Nausea, abdominal pain, loose stools, vomiting and fever can occur, but similar symptoms may have other explanations. The timing of a meal alone cannot identify the responsible food.

The main concern is fluid and salt loss. Dehydration may cause a dry mouth, dizziness, unusual tiredness, dark urine or passing urine less often. Young children, older adults, pregnant people and those with significant medical conditions may need earlier advice.

Take frequent small sips of water or an oral rehydration solution. If vomiting makes drinking difficult, pause briefly and restart with smaller sips. When appetite returns, try light foods and avoid alcohol. Wash hands carefully and avoid preparing food for others while unwell.

Do not take antibiotics or anti-diarrhoeal medicines without clinical advice; the right choice depends on the illness and your circumstances. A clinician may recommend oral rehydration therapy, and IV fluid therapy may be needed when dehydration is severe or fluids cannot be kept down.

Get urgent medical help for blood in vomit or stool, severe or worsening abdominal pain, confusion, fainting, severe dehydration, trouble breathing or inability to keep fluids down. Contact a clinician promptly for persistent fever, ongoing vomiting or diarrhoea, or illness after a high-risk exposure. Children, older adults and pregnant people should seek advice sooner if drinking or urination falls.

Could my symptoms be food poisoning or another illness? How much oral rehydration should I take? Which medicines should I avoid? Do I need testing or IV fluids? When can I safely return to work, school or food preparation?