Food poisoning is sudden illness caused by consuming food or drink contaminated with an infectious organism or toxin. Bacteria that can cause food poisoning include Salmonella, Campylobacter, Escherichia coli, Staphylococcus, Listeria, Clostridium difficile, and Clostridium botulinum (which causes botulism).
Viral causes include norovirus, rotaviruses, and some adenoviruses. Protozoal infections include cryptosporidiosis , amebiasis, and giardiasis.
Food poisoning can be caused by eating poisonous mushrooms or food contaminated with high doses of pesticides. The main symptoms include nausea, vomiting, diarrhea, and abdominal cramps. Some food poisoning may cause more widespread symptoms; for example, botulism may cause muscle weakness and paralysis.
In most cases, symptoms clear up by themselves within a few days. They can be relieved by self-help measures, such as drinking plenty of fluids and eating a bland diet. If symptoms are severe or prolonged, or if other, unusual symptoms develop (muscle weakness or paralysis, for example), medical advice should be sought.