What to do if you have food poisoning symptoms

Food can become contaminated at any stage during its production, processing or cooking.

Índice Show

Types of infection
Campylobacter
Escherichia coli (E. coli)

For example, it can become contaminated by:

not cooking food thoroughly (particularly meat)
not correctly storing food that needs to be chilled at below 5C
keeping cooked food unrefrigerated for a long period
eating food that has been touched by someone who is ill or has been in contact with someone with diarrhoea and vomiting
cross-contamination (where harmful bacteria are spread between food, surfaces and equipment)

Cross-contamination can occur, for example, if you prepare raw chicken on a chopping board and don't wash the board before preparing food that won't be cooked (such as salad), as the harmful bacteria can be spread from the chopping board to the salad.

It can also occur if raw meat is stored above ready-to-eat meals and juices from the meat drip on to the food below.

See preventing food poisoning for information about reducing these risks

Types of infection

Food contamination is usually caused by bacteria, but it can also sometimes be caused by viruses or parasites. Some of the main sources of contamination are described below.

Campylobacter

In the UK, campylobacter bacteria are the most common cause of food poisoning. The bacteria are usually found on raw or undercooked meat (particularly poultry), unpasteurised milk and untreated water.

The incubation period (the time between eating contaminated food and the start of symptoms) for food poisoning caused by campylobacter is usually between two and five days. The symptoms usually last less than a week.

Salmonella

Salmonella bacteria are often found in raw or undercooked meat, raw eggs, milk, and other dairy products.

The incubation period is usually between 12 and 72 hours. The symptoms usually last around four to seven days.

Listeria

Listeria bacteria may be found in a range of chilled, "ready-to-eat" foods, including pre-packed sandwiches, cooked sliced meats and pâté, and soft cheeses (such as Brie or Camembert).

All of these foods should be eaten by their "use-by" dates. This is particularly important for pregnant women, because a listeria infection (known as listeriosis) in pregnancy can cause pregnancy and birth complications, and can result in miscarriage.

The incubation period can vary considerably, from a few days to several weeks. The symptoms will usually pass within three days.

Escherichia coli (E. coli)

Escherichia coli, often known as E. coli, are bacteria found in the digestive systems of many animals, including humans. Most strains are harmless but some can cause serious illness.

Most cases of E. coli food poisoning occur after eating undercooked beef (particularly mince, burgers and meatballs) or drinking unpasteurised milk.

The incubation period for food poisoning caused by E. coli is typically one to eight days. The symptoms usually last for a few days or weeks.

Shigella

Shigella bacteria can contaminate any food that has been washed in contaminated water.

Symptoms typically develop within seven days of eating contaminated food and last for up to a week.

An infection caused by Shigella bacteria is known as bacillary dysentery or shigellosis. See the topic on dysentery for more information about it.

Viruses

The virus that most commonly causes diarrhoea and vomiting is the norovirus. It's easily spread from person to person, through contaminated food or water. Raw shellfish, particularly oysters, can also be a source of infection.

The incubation period typically lasts 24-48 hours and the symptoms usually pass in a couple of days.

In young children, the rotavirus is a common cause of infection from contaminated food. The symptoms usually develop within a week and pass in around five to seven days.

Parasites

In the UK, food poisoning caused by parasites is rare. It's much more common in the developing world.

Parasitic infections that can be spread in contaminated food include:

giardiasis – an infection caused by a parasite called Giardia intestinalis
cryptosporidiosis – an infection caused by a parasite called Cryptosporidium
ameobiasis – a type of dysentery caused by a single-cell parasite (ameoba) called Entamoeba histolytica (this is very rare in the UK)

The symptoms of food poisoning caused by a parasite usually develop within 10 days of eating contaminated food, although sometimes it may be weeks before you feel unwell.

If left untreated, the symptoms can last a long time – sometimes several weeks or even a few months.

Medically Reviewed by Dan Brennan, MD on November 10, 2020

Remedies for Food Poisoning
When to See a Doctor

Food poisoning is an illness you get from eating food that has bacteria, a virus, or a parasite in it. Symptoms can begin hours, days, or weeks after ingestion — depending on the type of infection — and can include:

Vomiting
Nausea
Diarrhea
Stomachache
Fever

Here are some of the organisms that may cause food poisoning:

Campylobacter, bacteria found in contaminated or poorly processed foods and drinks
Escherichia coli (E. coli), usually found in raw vegetables and undercooked meat
Listeria, which can be present in deli meats and soft cheeses
Norovirus, which you can get from undercooked shellfish
Salmonella, typically found in undercooked poultry and raw eggs
Staphylococcus aureus, which can also cause staph infections

You likely won’t get sick every single time you come into contact with one of these organisms. Older people, infants, young children, pregnant people and their unborn offspring, and people with compromised immune systems are more at risk of becoming ill from foodborne pathogens.

Poor food handling is the main reason people get foodborne illnesses. To lessen the chances of food poisoning, do the following:

Wash hands and dishes frequently in hot, soapy water.
Wash raw vegetables or fruits.
Handle raw food — especially meat — in a sanitary way.
Refrigerate or freeze perishables that need to be stored promptly.
Cook meat to the proper temperature.
Defrost frozen food safely and cook it immediately.

If you take a food item out of your fridge and pantry and it looks questionable, just throw it away.

Some remedies for food poisoning ease the symptoms, while others help to prevent dehydration, which can make symptoms worse.

Resting Your Body

Simple rest is one way to help your body heal from food poisoning. Take it easy until you are feeling better.

Additionally, do not eat or drink for a few hours after the onset of symptoms. Once you do start eating and drinking again, try gentle and bland foods, like crackers, and sports drinks. Suck on ice chips to stay hydrated.

Hydrating With Electrolytes

One of the most common complications of any foodborne illness is dehydration, especially among young children and older adults. The condition can be fatal if it’s not treated right away.

Dehydration due to common symptoms of food poisoning — diarrhea and vomiting — can cause you to lose a lot of fluid in a short time. A lack of fluids in the body can cause tiredness, weakness, and sometimes even irregular heartbeats.

Unless the dehydration is severe, it’s often treatable at home and according to your doctor’s instructions. Sports drinks or water with electrolyte tablets can usually ease mild dehydration. Serious cases could necessitate going to a clinic or hospital immediately to get intravenous (IV) fluids directly into your body through your veins.

Following the BRAT Diet

The BRAT diet is gentle on the stomach and consists of bananas, rice, applesauce, and toast. Eat this for as long as you’re not feeling well. You can also include clear broths in this diet.

This diet contains foods that help make your stools firmer and helps to replenish nutrients you may have lost throughout your illness. If you choose not to follow this diet, make sure to eat smaller and low-fat meals until you are feeling better.

Adding Probiotics to Your Meals

Probiotics are organisms that help to keep your gut biome in check. Everyone has bacteria living inside of them all the time. Some of these are “good bacteria,” and some are “bad bacteria.”

Food poisoning can throw off the delicate balance of good and bad bacteria in your gut. Taking probiotics can bring it back into balance. They may also strengthen your gut to protect you from future foodborne illness.

Taking Over-the-Counter Medicines

Over-the-counter medicines may stop the symptoms of food poisoning. Bismuth subsalicylate — you may know this medicine as Pepto-Bismol — can treat nausea and diarrhea. Loperamide — you may know this as Imodium — is an antidiarrheal that stops diarrhea by slowing down the digestive process.

It’s important to note that these products are generally not meant for children, however. The Food and Drug Administration (FDA) recommends that young children with diarrhea drink fluids and follow their regular diet, although diet changes and rehydration solutions may be needed if the problem continues.

Some doctors say that using over-the-counter medications may help you heal faster. However, other doctors say that it may be better to let the illness run its course without stopping nausea and diarrhea with over-the-counter remedies.

Drinking Ginger or Mint Tea

Ginger root is a staple in traditional medicine practices of multiple cultures. Studies show that it does relieve nausea in many cases.

Mint is also an herb that traditional medicine practitioners say can settle the stomach. It may have a pain-relieving application specific to the gut. Drinking tea can also help you stay hydrated while you are sick.

You can treat most cases of food poisoning at home. However, you should see a doctor if: