Everything You Need to Know About Food Poisoning

Published December 15th, 2021 by Corey Riley
Fact Checked by
Camille Freking
Medically Reviewed:
Dr. Angel Rivera
Updated Date: Jun 24th, 2022

What is food poisoning | Symptoms | Causes | Diagnosis | Treatment | Prevention

Food poisoning is an illness that occurs when food becomes contaminated with any number of bacteria, viruses, or parasites.

Food can become contaminated during food preparation, food storage, or while being eaten.

The symptoms of food poisoning are not always clear and may vary depending on the type of contaminant. Nevertheless, food poisoning often includes nausea, vomiting, and diarrhea.

There are many different types of food poisoning which include chemical contamination (toxic substances), bacterial infection (salmonella), and parasitic infections (giardia).

Please read on to learn more about food poisoning, its symptoms, and how to treat it.

What is food poisoning?

Food poisoning is a food-borne illness that occurs as the result of eating food or drinking water contaminated with bacteria, viruses, parasites, and toxins.

It is caused by food that is contaminated by mishandling it, not storing it properly, or not preparing the food in the proper manner.

Food poisoning is most commonly caused by bacteria such as staphylococcus and salmonella, but it can also be due to viruses like norovirus and hepatitis A, parasites like Giardia intestinalis, and toxins such as foodborne botulism.

What are the symptoms of food poisoning?

The symptoms of food borne diseases vary depending on what is causing it and how much food or water has been consumed, but there are some common symptoms that everyone may experience.

The most well-known symptom is vomiting because many different types of bacteria can cause an infected food to produce toxins that can irritate the lining of the stomach and intestines.

Other symptoms include:

  • nausea
  • diarrhea or constipation
  • stomach cramps or upset stomach
  • headache
  • fevers and chills
  • muscle aches
  • fatigue or drowsiness
  • severe dehydration and confusion
  • bloody diarrhea or bloody stool
  • appetite loss

The onset of food poisoning can be anywhere from 30 minutes after consuming the food or drink to up to 8 weeks later and it is all dependent on what exactly is causing your illness.

The symptoms will usually subside within one week although it is usually only takes a couple of days barring any complication of food poisoning.

What causes food poisoning?

There are three primary causes of food poisoning and they are viruses, parasites, and bacteria.

All of these organisms are capable of causing an individual to become ill if they consume food or water that is contaminated with them and some can even be spread person to person.

Viruses like norovirus or hepatitis A can cause food poisoning when they are transmitted from an infected individual to food and water.

Parasites such as the Giardia intestinalis parasite, which causes giardiasis also called beaver fever, can be contracted by eating food or drinking water that has been in contact with it.

There are many different types of bacteria that can contaminate food and water, but the most common are staphylococcus and salmonella. Below we will list the common viruses, parasites, and bacteria that cause foodborne illness.


  • Norovirus - a highly contagious virus that causes vomiting and diarrhea
  • Hepatitis A - affects the liver and can cause nausea, vomiting, abdominal pain, and jaundice
  • Rotavirus - a virus that causes severe diarrhea
  • Astrovirus - typically causes diarrhea in children
  • Sapovirus - another virus that causes severe diarrhea


  • Platyhelminthes - these consist of tapeworms and flatworms such as Taenia saginata, which is the beef tapeworm, and Taenia solium, which is the pork tapeworm
  • Nematodes - such as Trichinella spiralis, which is a roundworm that causes trichinosis
  • Protozoa - Giardia intestinalis, also called beaver fever, this parasite can cause abdominal cramps, bloating, and watery diarrhea falls in this category as does cryptosporidiosis and toxoplasma


  • E. Coli
  • Salmonella
  • Listeria monocytogenes, this bacteria causes listeriosis
  • Shigella
  • Vibrio vulnificus
  • Staphylococcus aureus, which is a type of staph infection
  • Clostridium botulinum, or the bacteria that causes botulism
  • Campylobacter
  • Streptococcus, the bacteria that can cause strep throat

How do you diagnose food poisoning?

There are many different ways to diagnose food poisoning and it will depend on the symptoms that you are experiencing.

If you are experiencing vomiting, diarrhea, and fever then your doctor may order a test for the presence of E. Coli bacteria or other sources of your symptoms in a stool sample.

Other tests that may be ordered include a blood test and a urine test.

The food you ate can also be tested if it is still preserved.

However, many cases can be diagnosed with your symptoms alone without any tests being taken at all.

How do you treat food poisoning?

There are many different ways to treat food poisoning, but some of the most common methods include staying hydrated by consuming lots of fluids and taking over-the-counter medications such as Bismuth subsalicylate, sold under the brand name as Pepto-Bismol, or loperamide, which can be found in Imodium.

Antibiotic treatment may be prescribed if food poisoning is caused by bacteria that can be treated with antibiotics or parasites that require drugs specific to them.

Treatment will also depend on what food caused food poisoning. For example, botulism needs an antitoxin unlike the other causes of food poisoning.

Lastly, you should get plenty of rest and hydrate as much as possible until your symptoms clear.

When you have food poisoning there are certain foods and drinks you should avoid so as not to exacerbate your symptoms.

Some of these foods include dairy products, caffeine, alcohol, fried foods, spicy foods, and high-fat foods.

There is a list of acceptable food and drink for infected people with foodborne illness symptoms and this list includes clear broths and soups, bananas, rice, crackers, and dry toast among a few others.

In fact, most solid foods are to be avoided and bland foods are your best option. 

How can you prevent food poisoning?

There are many ways that you can prevent food poisoning and they will depend on the food that is most likely to cause foodborne illness for you.

Some of the most common methods include washing your hands thoroughly with soap and water, keeping food at the correct temperature, avoiding cross-contamination, and cooking food to a safe temperature.

You can also get a food handler's certification which will help you learn more about food safety and how to prevent food poisoning.

The most common foods that give people food poisoning are meat, poultry, shellfish, dairy products, eggs, food containing them such as sauces or casseroles, deli meat, unpasteurized milk, and raw foods like sushi or undercooked meat.

Raw fruits are also common food items that cause food poisoning because of their high water content which can make it easy for bacteria to transfer along the food chain so be wary of any unwashed fruits.

To avoid a foodborne illness from these foods, we recommend following all the above advice about washing, handling, storing, and cooking food at the proper temperatures.


Food poisoning is a condition that can be caused by many different things, including bacteria, parasites, and viruses in contaminated water or food. It can cause nausea, vomiting, diarrhea, fever, and other unpleasant symptoms.

Treatment will depend on the food and source, for example parastitic infection vesus a bacterial infection, that is responsible for causing food poisoning and may include antibiotics or antidiarrheal medications.

Prevention tips include washing your food and hands thoroughly to avoid cross-contamination, cooking food at the correct temperatures, avoiding risky food choices such as raw meat or undercooked eggs, and getting a food handler's certification from your local Health Department.

Thank you for reading our article, if you have any further questions, we recommend talking to your doctor or pharmacist.

If you believe you have food poisoning, we recommend seeing your doctor or health care provider for medical treatment unless your symptoms are severe, then we recommend seeking immediate medical attention.

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Published December 15th, 2021 by Corey Riley
Fact Checked by
Camille Freking
Medically Reviewed:
Dr. Angel Rivera
Updated Date: Jun 24th, 2022

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