How Long Does Food Poisoning Last?

By Irmanie Hemphill, MD, FAAFP
Medically reviewed
September 21, 2021

Memories of a great meal can turn sour within a couple of hours as nausea sets in and it suddenly becomes clear: You’re the victim of food poisoning.

There are nearly 48 million cases of foodborne illnesses in the U.S. in a given year.

Even though these illnesses are common, the symptoms are still unpleasant, causing disturbances to your life and well being. 

When you’re experiencing food poisoning, you’re often waiting for it to pass—waiting as your body fights off the harmful bacteria, parasite, or virus.

The good news: Food poisoning will often resolve on its own.

In this article, I will discuss the different types of food poisoning and their incubation periods, so you know what to expect should you find yourself with a bout of food poisoning.

I’ll also offer some ways to avoid future bouts of food poisoning, and some advice on when you should talk to a doctor.

What is Food Poisoning?

Food poisoning is any of more than any 250 foodborne illnesses caused by eating contaminated food.

The most common pathogens of food poisoning are bacterial, viral, parasitic, or toxins. 

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Symptoms

Symptoms can vary depending on the type of food poisoning you’re experiencing.

But common symptoms of food poisoning include the following: 

  • Upset stomach
  • Stomach cramps and abdominal pain
  • Diarrhea (sometimes bloody diarrhea)
  • Vomiting
  • Nausea
  • Fever 

Causes

There are a number of germs that can cause food poisoning if you are exposed to them.

Some common types of bacteria include staphylococcus aureus (staph infections), vibrio, clostridium perfringens, salmonella, norovirus, botulism, listeria, and E. coli

These can be found on a variety of foods and food sources, but some common culprits include:

  • Raw and undercooked meats
  • Poultry
  • Shellfish
  • Eggs
  • Unpasteurized (raw) milk and dairy products
  • Unwashed leafy greens and fresh fruits
  • Improperly stored or canned foods
  • Nuts
  • Spices
  • Contaminated water
  • Food that is handled in an unsafe way by a sick individual
  • Food that has been cross-contaminated by raw or other contaminated foods

Treatment

Those with otherwise healthy immune systems will generally recover from food poisoning without formal treatment.

But depending on the severity of symptoms and type of illness, certain treatments can help.

One of the most common side effects of food poisoning symptoms is dehydration, so when treating food poisoning, it’s important to drink plenty of fluids.

Use oral rehydration solutions and electrolyte solutions to replenish the body if necessary.

In severe cases, IV fluids may need to be administered. Signs of dehydration include dry mouth and eyes, lightheadedness, and dark-colored urine with a strong smell. 

In certain cases of food poisoning and for certain symptoms, your doctor might prescribe antibiotics.

For example, food poisoning caused by listeria may need IV treatment in the hospital.

Certain over-the-counter medications can be used for nausea and vomiting if needed. 

When recovering from food poisoning, it’s best to eat bland foods or those that follow the BRAT diet, which consists of bananas, rice, apples, and toast.

Foods like ginger and ginger ale can also help calm your stomach and nausea.

Avoid spicy foods, caffeine, and alcohol, which can all disturb the stomach and cause gastrointestinal symptoms.

Food Poisoning Incubation Time

Food poisoning symptoms can set in anywhere from a few hours to a few weeks after eating contaminated food, depending on the type of illness you’re experiencing. 

Bacteria

Bacterial food poisoning is the most common type of foodborne illness in the United States.

Symptoms usually set in 8-48 hours after exposure.

The recovery time for a bacterial foodborne illness is 24 hours to 7 days. Some common bacterial foodborne illnesses come from E. coli bacteria (Escherichia coli), listeria bacteria, clostridium perfringens, and salmonella. 

Parasites

Symptoms of parasitic food poisoning, like giardia, generally last 2-6 weeks.

Symptoms normally start 1-2 weeks after exposure.

The state of an individual’s immune system, their age, and preexisting conditions may affect how long parasitic food poisoning lasts. 

Viruses

Viral food poisoning incubation periods can vary depending on the type of virus you have been contracted.

Norovirus generally lasts from 1-3 days. Hepatitis A, another type of viral infection, can last up to 6 months, but people generally only present symptoms for a few weeks. 

How to Prevent Food Poisoning

The best ways to prevent food poisoning is to practice food safety in the kitchen, while dining out, and when traveling in a foreign country. 

  • Wash your hands: Use soap, and wash your hands thoroughly and often. Also wash between cooking different dishes.
  • Clean utensils and kitchen surfaces: Wash these when you’re cooking, and between preparing different dishes to prevent cross-contamination.
  • Keep produce and meat separate: Doing so on the cutting board and when preparing food can prevent cross-contamination.
  • Ensure food is cooked through: Thoroughly cooking food can kill germs that may cause foodborne illnesses. When preparing raw meat, use a thermometer to track the internal temperature.
  • Refrigerate leftovers within two hours: This can prevent spoilage.
  • Thaw food in the refrigerator: Don’t thaw food in the sink or on the counter; thaw it in the refrigerator, and cook immediately upon defrosting.
  • Dispose of food you’re not sure about: If you don’t know if food has been stored properly or how it was prepared, be safe and throw it away. Even if it smells and looks fine, it may not be completely safe to eat. 
  • Check expiration dates: Be sure food is not expired to avoid foodborne illness.

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When To See a Doctor

In rare cases, symptoms can become severe and life threatening.

If you experience any of the following severe symptoms, it’s important that you see a doctor or healthcare provider as soon as possible: 

  • Blood diarrhea or diarrhea that lasts more than three days
  • High fever (above 102°F) 
  • Inability to keep liquids down
  • Frequent vomiting, causing dehydration

Individuals who are immunocompromised, those with preexisting health conditions, and pregnant women are at risk of complications of food poisoning.

In severe cases, food poisoning can cause miscarriage, stillbirth, or premature delivery in pregnant women.

If you suspect you have been exposed to foodborne illness as a pregnant individual, it is best to seek medical attention. 

In severe cases of food poisoning, individuals have been hospitalized, and untreated illnesses can lead to long-term health problems, including brain and nerve damage, kidney disease and failure by hemolytic uremic syndrome (HUS), as well as arthritis. 

How K Health Can Help

Food poisoning usually goes away on its own. But if you have a worrying case of foodborne illness, a healthcare provider can tell you if it’s something to worry about, or if the illness will go away on its own.

Did you know you can get affordable primary care with the K Health app?

Download K to check your symptoms, explore conditions and treatments, and if needed text with a doctor in minutes. K Health’s AI-powered app is HIPAA compliant and based on 20 years of clinical data.

Frequently Asked Questions

How do you tell the difference between food poisoning and a stomach bug?
While food poisoning and a stomach bug can present similar symptoms, they spread differently and usually present with different severity and length of symptoms. The stomach flu (a term used interchangeably with a stomach virus, but officially known as viral gastroenteritis) is a viral infection that is transmitted from person to person. Symptoms include diarrhea, abdominal cramps, vomiting and sometimes fever. Food poisoning can also be caused by a virus, but comes from contaminated food and is not usually transmitted from person to person. The symptoms of food poisoning will often be more severe and begin sooner than the stomach virus, which has an incubation period of about 24-48 hours. Food poisoning usually resolves on its own in 1-2 days, while the stomach flu can last 1-3 days (although sometimes longer). It’s important you know what is causing your symptoms so you can properly treat your illness.
What are the different types of food poisoning?
Food poisoning is caused by food that is contaminated by a bacteria, virus, parasite or toxins. The most common viral and bacterial causes of food poisoning are campylobacter, clostridium perfringens, E. coli, listeria, norovirus, and salmonella.
Is food poisoning contagious?
Food poisoning caused by certain bacterias, viruses, or parasites can be contagious. If you are sick with food poisoning and caring for a child or older adult, it is best not to prepare their food. Disinfect your home using soap, and clean the bathrooms. It is also best to stay home from work or school until symptoms disappear.
K Health articles are all written and reviewed by MDs, PhDs, NPs, or PharmDs and are for informational purposes only. This information does not constitute and should not be relied on for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.

Irmanie Hemphill, MD, FAAFP

Dr. Hemphill is an award winning primary care physician with an MD from Florida State University College of Medicine. She completed her residency at Halifax Medical Center.