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Medical Author:

Benjamin Wedro, MD, FACEP, FAAEM

Benjamin Wedro, MD, FACEP, FAAEM

Dr. Ben Wedro practices emergency medicine at Gundersen Clinic, a regional trauma center in La Crosse, Wisconsin. His background includes undergraduate and medical studies at the University of Alberta, a Family Practice internship at Queen's University in Kingston, Ontario and residency training in Emergency Medicine at the University of Oklahoma Health Sciences Center.

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Medical Editor:

Charles Patrick Davis, MD, PhD

Charles Patrick Davis, MD, PhD

Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.

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In this Article

• Food poisoning facts
• What is food poisoning?
• What are the types of food poisoning?
• What are the causes of food poisoning?
• What are the signs and symptoms of food poisoning?
• Are food poisoning and stomach flu the same thing?
• When should the doctor be called for food poisoning?
• How is food poisoning diagnosed?
• What is the treatment for food poisoning?
• Are there any home remedies for food poisoning?
• How long does food poisoning last?
• What are the complications of food poisoning?
• How can food poisoning be prevented?
• What is the prognosis for food poisoning?
• Summer Food Safety FAQs
• Patient Comments: Food Poisoning - Causes
• Patient Comments: Food Poisoning - Experience
• Patient Comments: Food Poisoning - Treatment
• Patient Comments: Food Poisoning - Symptoms
• Find a local Doctor in your town
• Food Poisoning Index

Most times, the diagnosis of food poisoning is made by history and physical examination. Often, the patient volunteers the diagnosis when they come for medical care. For example, "I got sick after eating potato salad at a picnic" or "I drank a raw egg protein shake".

The health care practitioner may ask questions about the symptoms, when they started, and how long they have lasted. A review of systems may help give direction as to what type of infection is present. For example, a patient with numbness of their feet and weakness may be asked about whether they have opened any home canned food recently.

Travel history may be helpful to see if the patient had been camping near a stream or lake and the potential for drinking contaminated water, or if they have travelled out of the Country recently and have eaten different foods than they normally do, for example, did the patient eat raw eggs or wild game?

Physical examination begins with taking the vital signs of the patient (such as blood pressure, pulse rate and temperature). Clinical signs of dehydration include dry, tenting skin, sunken eyes, dry mouth, and lack of sweat in the armpits and groin. In infants, in addition to the above subtle signs of dehydration may include poor muscle tone, poor suckling, and sunken fontanelle.

Routine blood tests are not usually ordered unless there is concern about something more than the vomiting and diarrhea. In patients with significant dehydration, the health care practitioner may want to check electrolyte levels in the blood as well as kidney function. If there is concern about hemolytic uremic syndrome, a complete blood count (hemogram, CBC) to check the red blood cells, white blood cells, and platelet count may be ordered. If there is concern about hepatitis, liver function tests may be ordered.

Stool samples may be useful especially if there is concern about infections caused by Salmonella, Shigella and Campylobacter, the common non traveler's diarrhea This is especially true when the patient presents with bloody diarrhea, thought to be due to infection. If there is concern about a parasite infection, stool samples can be examined also for the presence of parasites.

Depending on the suspected cause of the food poisoning, there are some immunological tests (for example, detection of Shiga toxins) that the CDC recommends. Other methods may be used (for example, detection of prions in tissue samples).