Food poisoning or foodborne illness 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 are pregnant, older than 65 or have a weakened immune system. Young children are also more at risk, especially from dehydration.
Food poisoning, or foodborne illness, occurs when you eat contaminated food. Contaminated means it’s infected with a toxic organism, such as a bacteria, fungus, parasite or virus. Sometimes the toxic byproducts of these organisms cause food poisoning.
When you eat something toxic, your body reacts to purge the toxins. You may purge through vomiting, diarrhea, fever or all of these. 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.
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Food poisoning and stomach flu are both gastrointestinal infections. They both cause gastroenteritis, which is inflammation of your stomach and small intestine. Gastroenteritis is the sign that your immune system has been activated to remove the infection.
Many of the same viral, bacterial and other infections can cause food poisoning or stomach flu, resulting in the same symptoms. The main difference is that foodborne illness comes from food, whereas you may catch a stomach bug in a variety of other ways.
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 it was something typically associated with food poisoning, or if you were with someone else who also got sick.
It’s very common. According to the CDC, about 48 million people a year experience some type of food poisoning in the United States. Most cases are not serious. However, about 3,000 people a year die from complications related to foodborne illness.
Anyone can get food poisoning if they eat contaminated food. But some people are more likely to get sick from contamination than others. It has to do with how much toxicity your body can normally tolerate without getting sick.
Our immune systems constantly fend off infections without our knowing about it. Even with sanitary food handling practices, there is usually a small amount of contamination in our food. It becomes “poisonous” when our immune systems reach their threshold.
You may be more likely to get sick from food poisoning, or have a more severe reaction to food poisoning, if your immune system is not as strong as average. Temporary things can impact your immunity, as well as longer-term conditions, such as:
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 is not:
Food poisoning occurs everywhere, but it’s especially easy to get it when traveling abroad, where you might encounter infectious pathogens that you wouldn’t at home. When you get it this way, it’s sometimes called traveler’s diarrhea.
Food and water may be contaminated by:
There are more than 250 specific types of food poisoning. Some of the most common causes include:
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.
The most common symptoms of food poisoning include:
It depends on the type of infection. Some of the most common bacterial infections 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.
Most of the time, food poisoning passes within 12 to 48 hours. That’s how long it takes for a healthy body to purge the infection. It may last longer if you have a weakened immune system, or if you have a parasite that needs to be treated with antiparasitic drugs.
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 stool sample or give you a blood test to check for particular parasites or bacteria.
In most cases, you can manage food poisoning 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.
Hydration formulas such as Pedialyte™ can be helpful when you’re sick. These formulas help fluids 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.
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, and often they won’t help. Some types of infections may even worsen with antibiotics.
Healthcare providers don’t typically prescribe antidiarrheal medications for food poisoning because they can prolong the illness. However, you may be able to relieve some of your symptoms with over-the-counter bismuth subsalicylate (Pepto Bismol®).
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 popsicles or gelatin are other options that can offer you a little sugar 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 add bulk to your stools.
Safe food handling practices are the most important way to prevent foodborne illness. Those who harvest, handle and prepare food need to be vigilant at every stage of the process to prevent contamination. For example:
Most people will recover without intervention in a day or two. 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 children.
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:
Call your healthcare provider if you are pregnant or breastfeeding, or if you are caring for a child who is having trouble keeping fluids down. Children become dehydrated more easily than we do. Call if you or your child have any unusual symptoms, such as:
Stay home for at least 48 hours after you have had diarrhea or vomited. Stay home 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 were infected while you were there.
A note from Cleveland Clinic
Even in modern, developed nations where food handling practices are relatively sanitary, food poisoning still commonly occurs. You may be even more at risk if you travel abroad. For the most part, our immune systems are well-equipped to deal with the occasional infection.
However, certain infections can cause serious side effects, especially in the more vulnerable among us. If you are concerned or immunocompromised, or if you have severe or unusual symptoms, don't hesitate to see your healthcare provider for testing and treatment.
Last reviewed by a Cleveland Clinic medical professional on 06/15/2022.
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