Food poisoning symptoms usually begin to appear within a range of a few hours to a few days after eating contaminated food. Commonly, symptoms start within 2 to 6 hours, with some types causing symptoms as early as 30 minutes to 6 hours after ingestion. The exact timing depends on the type of bacteria, virus, or toxin involved:
- For Staphylococcus aureus, symptoms can appear very quickly, often within 30 minutes to 6 hours.
- Bacterial causes like Salmonella or Clostridium perfringens typically take 6 to 24 hours, but can be up to a few days.
- Viral infections like Norovirus usually cause symptoms in 12 to 48 hours.
- Parasites may take a week or longer for symptoms to develop.
Thus, food poisoning can take anywhere from half an hour up to several days to come on, depending on the cause. Most commonly, people notice symptoms around 6 hours after eating contaminated food.