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Food Poisoning: Key Takeaways

• Symptoms of food poisoning can last anywhere from a few hours to several days and even 2-4 weeks. In most people, food poisoning lasts for 12 to 48 hours.

• Food poisoning symptoms can be more severe for children, pregnant women, elderly, and people with weakened immune systems. Other contributing factors include how much of the germ was consumed, as well as the strain of germ.

• Beside rest and getting well-hydrated, most people recover from food poisoning without needing any specific treatment from a healthcare provider.  

Food Poisoning vs Foodborne Illness vs Stomach Flu (Gastroenteritis)

Food poisoning is a gastrointestinal infection caused by viruses, bacteria, or parasites that are found in contaminated food and beverages. The symptoms of food poisoning occur due to toxins produced by the microbes present in contaminated foods.

Foodborne illnesses arise from eating contaminated food or drinking contaminated water. Food poisoning is, therefore, a type of foodborne illness. The Centers for Disease Control and Prevention (CDC) estimates there are 48 million cases of food poisoning or foodborne illnesses in the U.S. each year.

Stomach flu (also called gastroenteritis) is caused by contagious bacteria and viruses that spread from person to person. The most common ways to catch the stomach flu are by touching contaminated surfaces, by skin-to-skin contact with an infected person, and from contaminated foods and drinks handled by an infected person.

Check out our blog to learn more about the differences between food poisoning vs stomach virus.

Common Causes of Food Poisoning

Food poisoning is caused by germs found in meats, poultry, dairy products such as unpasteurized milk and soft cheeses, raw eggs, raw fish, and raw food such as fruits and vegetables. The following microbes commonly cause food poisoning:

• Bacillus

• Salmonella 

• Campylobacter

• Clostridium perfringens

• Clostridium botulinum

• Cryptosporidium

• Cyclospora

• Listeria

• Staphylococcus aureus

• Escherichia coli (E. coli)

• Shigella

• Vibrio

• Norovirus

• Hepatitis A

Symptoms of Food Poisoning To Watch For

Common symptoms of food poisoning include:

• Stomach pain 

• Stomach cramps

• Watery or bloody diarrhea

• Nausea

• Vomiting

• Bloating or gas

• Headache

• Fever and flu-like symptoms

Food poisoning symptoms can vary from person to person, ranging from mild to severe. 

Symptoms can start any time after eating contaminated food, from as little as 30 minutes to 3 weeks later, depending on the bacteria or virus in the food.

In most cases, food poisoning symptoms start within 1-3 days of exposure to contaminated foods and beverages. 

Food poisoning typically has a quicker onset (within 2-6 hours) compared to stomach flu (24-48 hours). 

How Long Does Food Poisoning Last?

Symptoms of food poisoning can last anywhere from a few hours to several days and even 2-4 weeks. In most people, food poisoning lasts for 12 to 48 hours. Here are some general timelines of food poisoning caused by common organisms:

What Factors Can Affect Duration of Illness? 

The severity and duration of food poisoning symptoms depend on various risk factors, including:

• Age: People of all ages can get food poisoning. However, very young children, older adults, and pregnant women are at risk of experiencing severe food poisoning. 

• Health Status: People with weakened immune systems and chronic health conditions such as kidney disease, diabetes, cancer, and HIV/AIDS (human immunodeficiency virus/acquired immunodeficiency syndrome) can develop severe symptoms. 

• Strain of Germ Ingested: Some strains of bacteria and viruses cause more dangerous and longer-lasting food poisoning than others.

• Exposure: The severity and duration of food poisoning also depend on the quantity of germs or toxins ingested. For example, you may have a mild, short-lived illness if you only ate a small bite of contaminated food. For this reason, food poisoning sometimes affects one person and spares others who ate the same food.

Stages of Food Poisoning

Food poisoning usually progresses through the following stages:

• Incubation: The incubation stage is the time between eating food contaminated by germs and the appearance of symptoms. During this stage, you remain unaware of the impending illness while the microbe multiplies in your body. The incubation stage of food poisoning can range from 30 minutes to 3 weeks but is typically 1-3 days. 

• Prodromal stage: During the prodromal stage, the germs continue multiplying in your body, activating your body’s immune system. This can cause mild, nonspecific symptoms such as tiredness and low energy. The prodromal stage can last for several hours to several days.

• Illness: In the illness stage, you have the symptoms of food poisoning. This stage can last anywhere from a few hours to several weeks, but it is typically 12-48 hours.

• Recovery: The recovery period is when you regain your health. It can take up to one week for you to start feeling like your usual self after food poisoning symptoms go away.

How is Food Poisoning Treated?

Home Remedies for Food Poisoning

• Get enough rest and sleep. 

• Drink plenty of fluids to prevent dehydration. You can drink water, fruit juices, broths, and sports drinks. Oral rehydration solutions (ORS) are available at pharmacies and drug stores. ORS can be used to replace fluids and minerals lost through vomiting and diarrhea. 

• Eat bland foods and low-acid foods. Avoid spicy foods. Doctors recommend the BRAT diet (bananas, rice, apple sauce, toast) which is easy to digest. It helps to control nausea and vomiting and gives your gastrointestinal system a chance to recover.

• Take over-the-counter medications, such as loperamide (Imodium) and bismuth subsalicylate (Kaopectate, Pepto-Bismol), to treat diarrhea.

• Use supplements such as probiotics, which can shorten the duration of a diarrheal illness. Check with your doctor before taking any over-the-counter supplements.

Prescription Medications for Food Poisoning

Prescription drugs are usually not necessary to treat food poisoning. However, if you have had food poisoning diagnosed and have a severe illness, your doctor may prescribe:

• Antibiotics for food poisoning caused by bacteria.

• Intravenous fluids to treat severe dehydration.

• Treatments for life-threatening or serious complications. 

When to Consult a Healthcare Provider

Most people recover from food poisoning without needing treatment from a healthcare provider. However, it’s important for vulnerable people to seek medical care, such as young children, older adults, and pregnant women. You should also call your doctor if you have the following serious symptoms:

• Blood or pus in the stool

• Fever above 101°F (38.3°C)

• Inability to keep down fluids

• Signs of dehydration (dry mouth, increased thirst, lightheadedness)

• Diarrhea that lasts more than 5 days or is worsening

• Persistent vomiting for more than 12 hours

Also, call your doctor if you:

• Have a weakened immune system

• Take medications such as diuretics (water pills) or ACE inhibitors (blood pressure pills)

• Traveled recently to a foreign country

• Have suspected botulinum or food poisoning from mushrooms or seafood

Ways to Prevent Food Poisoning At Home

Proper food storage, handling, cooking, and cleaning are necessary to prevent food poisoning:

• Store raw animal-origin foods like meat, seafood, poultry, and eggs separate from other foods.

• Wash your hands before and after handling raw meat, seafood, poultry, and eggs.

• Refrigerate or freeze perishable foods promptly. Foods that can spoil should not be left unrefrigerated for more than 2 hours or at temperatures above 90 degrees for more than 1 hour.

• Wash raw fruits and vegetables before cutting, cooking, or eating them.

• Cook foods at a high temperature and for long enough to kill germs (use a food thermometer, if needed).

• Keep utensils and kitchen surfaces clean. 

Ways to Prevent Food Poisoning When Traveling Abroad

If you are traveling to countries where foodborne illnesses are common, the National Institute of Diabetes and Digestive and Kidney Diseases recommends the following precautions. To prevent food poisoning or traveler’s diarrhea, you should avoid:

• Drinking or brushing your teeth with unbottled or untreated water. Remember, ice, ice chips, and foods and drinks prepared with untreated water may contain microbes

• Drinking unpasteurized juice, milk, and milk products like yogurt or cheese. 

• Eating food from street vendors

• Eating food that isn’t served hot

• Eating frozen food or deli meats that may not have been stored at the correct temperature

• Eating raw or undercooked meat; raw or undercooked shellfish, fish, or other seafood; raw or undercooked poultry; and raw or undercooked eggs

• Eating raw produce (raw vegetables and fruits) that you haven’t washed or peeled yourself