Food Poisoning

What Is It?

Most commonly, food poisoning is a reaction to food or water contaminated during improper cooking, handling or storage. The most common contaminants are bacteria, such as salmonella, Campylobacter and E. coli. Other contaminants include viruses, parasites and toxins. Food poisoning usually leads to abdominal cramping, vomiting and diarrhea.

Food poisoning, although common, often can be prevented easily. An estimated 85% of food-poisoning incidents can be prevented by handling and preparing food properly. Usually, symptoms subside within a day or two. However, in some cases, food poisoning is quite dangerous.


Symptoms of food poisoning include:

  • Nausea and vomiting

  • General weakness

  • Abdominal pain/cramping

  • Diarrhea

  • Fever


The diagnosis is usually made on the basis of symptoms alone, and fortified if there is an accompanying history of a person eating with you who also became sick. If a doctor wants to pinpoint the microorganism that caused the food poisoning, you will be asked to provide a stool sample to be examined in a laboratory. Your doctor also may want to take a sample of your blood for testing. If you have some of the food that might have made you sick, ask your doctor if it is important to test for infectious organisms or a toxin. The sample can be cultured in a laboratory, which means it is placed on a special material that encourages organisms that may be in the sample to grow, so they can be identified.

To continue reading this article, you must login.
  • Research health conditions
  • Check your symptoms
  • Prepare for a doctor's visit or test
  • Find the best treatments and procedures for you
  • Explore options for better nutrition and exercise
Learn more about the many benefits and features of joining Harvard Health Online »