Food poisoning symptoms typically start within a few hours after eating contaminated food, but the exact time can vary depending on the type of bacteria or virus involved. Generally, symptoms can begin as soon as 30 minutes to 6 hours, with most common cases around 6 hours after ingestion. However, some bacteria like Salmonella or Campylobacter may take 2 to 5 days to show symptoms, and viruses like Norovirus usually cause symptoms 24 to 48 hours after exposure.

Typical Onset Times by Common Causes:

• Staphylococcus aureus: symptoms like nausea, vomiting, and cramps can begin within 30 minutes to 8 hours.
• Clostridium perfringens: diarrhea and cramps typically start 6 to 24 hours after eating contaminated food.
• Salmonella: symptoms typically appear 6 hours to 6 days post-consumption.
• Campylobacter: symptoms start between 2 to 5 days.
• Norovirus: symptoms typically appear within 24 to 48 hours.

Common Symptoms:

• Nausea, vomiting
• Diarrhea (sometimes bloody)
• Stomach cramps
• Fever and headache in some cases

The timing and severity of symptoms also depend on factors like the amount of contaminated food consumed and individual susceptibility. Most food poisoning symptoms resolve within a few days, but severe cases may require medical attention.