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Food Poisoning Signs and Symptoms


Updated March 22, 2014

Written or reviewed by a board-certified physician. See About.com's Medical Review Board.

The signs and symptoms of bacterial food poisoning, or 'foodborne illness,' include digestive system complaints and usually start within a few hours after you eat contaminated food. But they may take as long as a few days to start, depending on which bacteria are making you sick.

  • abdominal cramps
  • diarrhea
  • fever
  • nausea
  • vomiting
  • headache
  • weakness
  • abdomen is tender to touch
  • dehydration

Infants and young children, pregnant women, elderly people, and people with weakened immune systems need medical attention for food poisoning. Anyone else should seek medical treatment if the food poisoning signs don't improve in a day or two.

The number of cases of food poisoning goes up during the summer months when the bacteria grow faster in the warmer temperatures. Since summer is a great time for picnics and barbecues, be sure to follow food safety rules for transporting and storing foods outdoors.

Prevent Food Poisoning

  • Wash your hands before cooking, before serving and before eating meals.
  • Keep raw meat, eggs, and poultry away from any other foods that are ready to be served.
  • Use clean knives, utensils and cutting boards, and don't cross contaminate raw meats and poultry with fruits and vegetables.
  • Wash fresh fruits, vegetables and bagged greens.
  • Keep cold food refrigerated under 40 degrees Fahrenheit.
  • Hot foods should be kept at 140 degrees or above.
  • Beef, veal and lamb should be cooked to an internal temperature of 145 degrees.
  • Pork and ground beef, veal and lamb should be cooked to 160 degrees.
  • Poultry needs to be cooked to 165 degrees.
  • Reheated food should be heated to 165 degrees before it's served.

Bacteria and More

Food poisoning is usually caused by bacteria, but ingesting poisonous foods -- such as certain mushrooms or shellfish, or eating seafood harvested from contaminated water -- can cause similar symptoms. These forms of food poisoning are an emergency, and you need treatment immediately.

Common types of bacteria involved in food poisoning:


U.S. Department of Agriculture. Food Safety and Inspection Service. "Foodborne Illness: What Consumers Need to Know." Accessed March 24, 2011. http://www.fsis.usda.gov/Fact_Sheets/Foodborne_Illness_What_Consumers_Need_to_Know/index.asp.

U.S. Department of Health and Human ServicesNational Institutes of Health. "Food Poisoning." Accessed March 24, 2011. http://www.nlm.nih.gov/medlineplus/ency/article/001652.htm.

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