Gastro Health

Food Poisoning - Symptoms, Causes, Diagnosis, Treatment and Prevention

Written by
Dr. Sneha Kannan
and medically reviewed by Dr. Jagdish Singh

Published on Oct 23, 2019   -  4 min read



Food poisoning is caused by eating food contaminated with bacteria or other pathogens, and it results in vomiting, diarrhea, and stomach pain. To know more, read the article.

Food Poisoning - Symptoms, Causes, Diagnosis, Treatment and Prevention

What Is Food Poisoning?

Food poisoning, otherwise called foodborne illness, is caused by eating food contaminated with infectious organisms (bacteria, viruses, and parasites) or toxins or eating spoiled food. Food can get contaminated at any stage of processing or production or preparation. The symptoms start within hours of eating food contaminated with toxins. The symptoms include nausea, vomiting and diarrhea. Mostly, food poisoning is mild and does not require treatment. But in severe cases, it can cause dehydration and might require hospitalization.

It is a common infection, and according to the Centers for Disease Control and Prevention (CDC), 1 in 6 people in the US get some kind of food poisoning every year.

What Are the Symptoms of Food Poisoning?

Depending on the cause of infection, your symptoms and length of the symptoms can vary. As soon as you eat contaminated food, you might start having symptoms from anywhere after an hour to 28 days. The common symptoms of food poisoning are:

  • Stomach cramps.

  • Diarrhea.

  • Nausea.

  • Vomiting.

  • Loss of appetite.

  • Chills.

  • Muscle pain.

  • Fever.

  • Tiredness.

  • Headaches.

If you have the following symptoms, get immediate medical help:

What Are the Risk Factors for Food Poisoning?

People that are at a higher risk to develop food poisoning are children, pregnant women, older adults, immunocompromised individuals, and people with diabetes, liver or kidney disease.

What Are the Causes of Food Poisoning?

The common causes of food poisoning are:

Viruses and bacteria - Viruses are the number one cause of food poisoning followed by bacteria. The most common microorganisms that cause food poisoning are:

  1. Norovirus.

  2. Salmonella.

  3. Clostridium perfringens.

  4. Campylobacter.

  5. Staphylococcus aureus.

  6. Toxoplasma gondii.

  7. Escherichia coli (E. coli).

  8. Listeria monocytogenes.

  9. Shigella.

  10. Rotavirus.

  11. Hepatitis A.

Toxins - Toxins produced by bacteria, plants, and animals (fish) can cause food poisoning if they are ingested. The common toxins include:

  • Bacteria - Enterotoxins, Exotoxins, Neurotoxins.

  • Plants - Mushroom toxins, Ricin, Hemlock.

  • Animals - Scombroid toxin, Sasitoxin, Tetrodotoxin.

Parasites - Some of the parasites that can cause food poisoning are:

  • Amoeba

  • Giardia

  • Trichinella

Chemicals - Chemicals like mercury in drinking water and fish can enter the body and cause food poisoning. Even if chemicals like pesticides, polychlorinated biphenyls, and lead in food, it can cause vomiting and diarrhea.

How Is Food Poisoning Diagnosed?

Your doctor will diagnose this condition after taking a detailed history of how long you are having symptoms and what food you have eaten. Your doctor will also look for signs of dehydration dry dry mouth.

If needed, your doctor will suggest getting diagnostic tests like a blood test and stool culture to identify the cause of food poisoning. The causative organism is detected in the stool sample sent to the laboratory.

How Is Food Poisoning Treated?

Food poisoning treatment depends on the cause and the severity of the symptoms. Most people get better on their own without any treatment in some days, but for some, it may last longer. The treatment includes:

  • Fluid replacement - Fluids and electrolytes like sodium, potassium, and calcium lost due to vomiting and diarrhea have to be replaced. Oral rehydration solutions (ORS) are commercially available for this purpose. For severe dehydration, fluids through IV (intravenous) has to be administered in the hospital.

  • Antibiotics - For infection caused by bacteria, your doctor will prescribe antibiotics. Infection caused by bacteria listeria is treated with IV antibiotics. In pregnant women, the infection can affect the baby, so antibiotics have to given promptly. Antibiotics will not be effective against food poisoning caused by viruses.

  • Loperamide and Bismuth subsalicylate - Can help adults with diarrhea.

Home Remedies:

Usually, food poisoning improves within 48 hours without treatment. To prevent complications like dehydration, try the following:

  • Avoid eating for a few hours and give your stomach some time to heal.

  • Rest.

  • Keep sippling water or ORS to prevent dehydration.

  • Start eating nonspicy and low-fat foods.

  • Avoid eating dairy products, caffeine, alcohol, and oily food.

  • Drink herbal tea.

What to Eat When You Have Food Poisoning?

Things that you can eat are:

  • Bananas.

  • Rice.

  • Clear soup.

  • Boiled vegetables.

  • Toast.

  • Fruit juices.

  • Oats.

What Not to Eat When You Have Food Poisoning?

Things you need to avoid are:

  • Milk and milk products.

  • High fatty food.

  • Sugary drinks.

  • Spicy food.

  • Fried foods.

  • Alcohol.

  • Caffeinated beverages.

Can Food Poisoning Be Prevented?

You can reduce the risk of food poisoning by:

  • Washing your hands frequently and properly.

  • Cook meats properly to the right temperature.

  • Do not mix raw food with cooked food.

  • Refrigerate food that will get spoiled properly.

  • Do not eat spoiled or old food.

  • Drink pasteurized milk.

  • Wash fruits and vegetables properly.

If your symptoms do not improve within 48 hours, it is best to consult a doctor. Persistent vomiting and diarrhea can result in severe dehydration, which can be life-threatening in infants, older adults, and immunocompromised individuals. For more information on food poisoning, consult a medical gastroenterologist online.

Last reviewed at:
23 Oct 2019  -  4 min read




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