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Food Poisoning

Food poisoning can happen to anyone who swallows contaminated food. Most people recover on their own, but some can become gravely ill. You’re more at risk if you’re pregnant, older than 65 or have a weakened immune system. Young children are also more at risk, especially from dehydration.

Overview

What is food poisoning?

Food poisoning occurs when you eat contaminated food. Contaminated means it’s infected with a toxic organism, like a bacterium, fungus, parasite or virus. Sometimes, the toxic byproducts of these organisms can cause food poisoning.

When you eat something toxic, your body reacts to purge the toxins. You may purge through vomiting, diarrhea or both. You may also develop a fever. The uncomfortable symptoms of food poisoning are your body’s way of working to return to health. It usually works in a day or two.

Who gets food poisoning?

Anyone can get food poisoning if they eat contaminated food, but some people are more likely to get sick from contamination than others. It depends on how much of the toxin they ingested and how concentrated it was.

Your overall health plays a role in your risk of getting food poisoning, too. Your immune system fends off infections all the time, and you don’t even know about it. Even with sanitary food handling practices, there’s usually a small amount of contamination in your food. It becomes “poisonous” when your immune system reaches its threshold.

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Symptoms and Causes

How do I know if I have food poisoning?

It can be hard to tell where an infection came from, especially if it took some days to develop symptoms. You may be able to trace it back to something you ate if:

  • You ate something commonly associated with food poisoning.
  • You were with someone else who also got sick.

What does food poisoning feel like?

The most common food poisoning symptoms include:

How soon after food poisoning do you vomit?

It depends on the type of infection. Some of the most common bacterial infections can take hold within a few hours. Others need time to incubate in your system before they become toxic. Some infections may take a few days, and some can take a few weeks.

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How do you get food poisoning?

You get it by eating or drinking contaminated food, water or other beverages. Food can become contaminated at any stage of production, from harvesting to storage to cooking or preparation. Contamination occurs when food isn’t:

  • Fresh.
  • Washed well.
  • Handled in a sanitary way.
  • Cooked to a safe internal temperature.
  • Held at proper temperatures.
  • Refrigerated or frozen promptly.

Food poisoning occurs everywhere. But it’s especially easy to get it when traveling abroad, where you might encounter germs that you wouldn’t at home. When you get it this way, it’s sometimes called traveler’s diarrhea.

What types of contaminants cause food poisoning?

Things that may contaminate food and water include:

  • Bacteria.
  • Viruses.
  • Parasites.
  • Fungi.
  • Toxins.
  • Chemicals.

There are more than 250 specific types of food poisoning. Some of the most common causes include:

  • Salmonella: Raw eggs and undercooked poultry are common sources of salmonella poisoning. It can also occur from beef, pork, vegetables and processed foods containing these items. Salmonella is the most common bacterial cause of food poisoning in the U.S. It causes the highest number of hospitalizations and deaths from food poisoning.
  • E. coli: Usually found in undercooked meat and raw vegetables, E. coli bacteria produce a toxin that irritates your small intestine.
  • Listeria: Bacteria in soft cheeses, deli meats, hot dogs and raw sprouts can cause listeriosis, an infection that’s especially dangerous for pregnant people.
  • Norovirus: You can get norovirus by eating undercooked shellfish, leafy greens or fresh fruits. You can also get it by consuming food prepared by a sick person. This is the virus most commonly associated with stomach flu.
  • Hepatitis A: Viral hepatitis A can be spread through shellfish, fresh produce or water and ice contaminated by poop. It’s not a chronic infection like other hepatitis viruses, but it can affect your liver.
  • Staphylococcus: A staph infection occurs when people transfer the staph bacteria from their hands to food. Foods that are often implicated are meats, poultry, milk and dairy products, salads, cream-filled baked goods and sandwich fillings. The bacteria can affect many parts of your body.
  • Campylobacter: This common bacterial infection producing severe GI upset can linger for weeks. Usually, culprits are undercooked poultry, meat or eggs, poorly processed meats, contaminated vegetables and raw (unprocessed) milk or water sources. It’s also spread by cross-contamination.
  • Shigella: Shigella bacteria is most typically found in uncooked vegetables, shellfish and cream or mayonnaise-based salads (tuna, potato, macaroni, chicken). It can cause blood or mucus in your diarrhea, which is why the infection is sometimes called bacillary dysentery.

Is food poisoning contagious?

The infection can spread from you to another person if they come into contact with your germs. Germs can spread through tiny particles of vomit or poop that linger on surfaces or on fingers and then transfer to another person’s food or mouth.

Who is most at risk from foodborne poisoning?

You may be more likely to get sick from food poisoning — or have a more severe reaction to food poisoning — if your immune system isn’t as strong as average. Things that can impact your immunity include:

  • Age. Children under the age of 5 have immature immune systems. Mature immune systems begin to decline after the age of 65.
  • Pregnancy. Pregnancy is demanding on your body, leaving you with fewer resources than usual to fight off infections.
  • Chronic illnesses. Many chronic conditions can affect your immunity, including infections, cancer, immunodeficiency diseases and autoimmune diseases.
  • Medications. Corticosteroids and immunosuppressants can repress your immune system and make you more prone to illness.

What are the possible complications associated with food poisoning?

While complications from food poisoning are rare, they can be severe and, in some cases, even fatal. Severe dehydration is the most common risk, but some specific types of infections can cause other specific complications. For example:

  • Miscarriage and stillbirth: Listeria infection is especially dangerous for a developing fetus because the bacteria can cause neurological damage and death.
  • Kidney damage: E. coli can lead to hemolytic uremic syndrome (HUS) and kidney failure.
  • Arthritis: Salmonella and campylobacter bacteria can cause chronic arthritis and joint damage.
  • Nervous system and brain damage: Some bacteria or viruses can cause a brain infection called meningitis. Others like campylobacter can cause a neurological disorder called Guillain-Barré syndrome.

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Diagnosis and Tests

How is food poisoning diagnosed?

Your healthcare provider will ask you about your symptoms and what you’ve had to eat and drink recently. If you have particular symptoms, they may want to take a poop sample or give you a blood test to check for particular parasites or bacteria.

Management and Treatment

Will food poisoning go away on its own?

In most cases, you can manage food poisoning through supportive therapy at home by simply staying hydrated. You lose a lot of fluids through diarrhea, vomiting and fever. Staying hydrated is the most important thing you can do to support your body while it does its work.

Food poisoning treatment may include hydration formulas like Pedialyte™ or any form of hydration that has balanced electrolytes, which can be helpful when you’re sick. These formulas help fluids and important electrolytes stay in your body longer. If you or your child are having trouble keeping fluids down or showing signs of dehydration, you might need to go to the hospital for IV fluids.

Do I need food poisoning medication?

Certain types of infections may require antibiotics. Your healthcare provider will work to determine if you have one of these types. Most of the time, antibiotics aren’t necessary. In some situations, antibiotics can even make food poisoning worse.

Healthcare providers don’t typically prescribe antidiarrheal medications for food poisoning because they can prolong the illness. But you may be able to relieve some of your symptoms with over-the-counter (OTC) bismuth subsalicylate (Pepto Bismol®).

Prevention

How can food poisoning be prevented?

Safe food handling practices are the most important way to prevent food poisoning. Those who harvest, handle and prepare food need to be alert at every stage of the process to prevent contamination. For example:

  • Clean: Wash raw produce well in clean, sanitary water. Wash your hands and utensils before using them to prepare food. Wash and clean (disinfect) all surfaces that your food will touch, including cutting boards, countertops and plates.
  • Separate: Avoid cross-contamination by separating raw meats and eggs from fresh produce or other food items. Cooking at proper temperatures will destroy germs on meat products. But if those germs transfer to uncooked items, they may survive and contaminate that food item.
  • Cook: Take care to cook meats and seafood thoroughly to the proper temperatures to kill germs. Whole cuts of meat can be pink on the inside if they’re well-seared on the outside. Ground meats need to be thoroughly cooked with no pink left. Fish should be opaque and not translucent, and easy to flake with a fork.
  • Chill: Refrigerate or freeze prepared foods within two hours of cooking to keep bacteria from breeding. If foods contain gravy, sauces, mayonnaise or creams, make sure they have held at proper temperatures while still serving them. Check your refrigerated foods for microbe growth like mold. Throw out dairy products if they’ve passed their expiration dates or have an “off” smell.

In addition, your public health department makes an effort to control food poisoning by informing citizens of possible outbreaks. Pay attention to public announcements of food recalls. If you get food poisoning, report it.

Outlook / Prognosis

What is the outlook for people who have food poisoning?

Most people will recover without intervention in a few days. If you or someone in your care has a particularly severe reaction to food poisoning, you might need medical intervention. The most common reason for this is dehydration, especially in those who are under 5, over 65, pregnant or have compromised immune systems.

How long does food poisoning last?

Most of the time, food poisoning passes within 24 to 48 hours. That’s how long it takes for a healthy body to purge the infection. It may last longer depending on how much toxin is in your system, if you have a weakened immune system, or if you have a parasite that requires treatment with antiparasitic drugs.

When can you return to work or school if you have had food poisoning?

Stay home, if possible, for at least 24 hours after a fever. Make sure to let your school or workplace know about the infection, especially if you or your child got an infection while you were there.

Living With

What should I eat and drink while I’m sick with food poisoning?

You may want to let your stomach settle for a while before introducing food or drinks. Try sucking on ice chips to stay hydrated without overwhelming your stomach. Fruit juice ice pops or gelatin are other options that can offer you nutrients, electrolytes and calories for energy.

When you feel prepared to begin eating again, start with small bites of bland foods. Some broth and crackers or toast would be a great choice. The sodium and water content in the broth can help you rehydrate, while the crackers can add bulk to your poop.

What makes food poisoning worse?

Certain foods and drinks can make food poisoning worse, including:

  • Fatty and fried foods.
  • Spicy foods.
  • Dairy.
  • Caffeine.
  • Alcohol.
  • High-fiber foods.
  • Nicotine.
  • Acidic foods.

When should I call my healthcare provider about food poisoning?

Call your healthcare provider if you’re pregnant or breastfeeding (chestfeeding), or if you’re caring for a child under 5 or a person over 65 who’s having trouble keeping fluids down. People in these age groups are more at risk for complications from dehydration. Call if you or your child have any unusual symptoms, like:

  • Persistent, high fever of over 102 degrees Fahrenheit (38.9 degrees Celsius).
  • Bloody diarrhea or vomit or unable to tolerate anything orally.
  • Dark pee or lack of pee.
  • Blurred vision.
  • Delirium or confusion.
  • Dizziness or lightheadedness.

A note from Cleveland Clinic

You probably feel awful right now. Diarrhea, vomiting, fever. All of these are symptoms of food poisoning that mean your body is trying to purge the toxin that has taken over. The good news is that food poisoning usually runs its course in a day or two. Just focus on staying hydrated and letting your body fight it off. If your condition persists or you develop more severe symptoms, see your healthcare provider for treatment.

Medically Reviewed

Last reviewed on 06/26/2024.

Learn more about the Health Library and our editorial process.

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