Food Poisoning

Advertisement - Scroll to continue

What is Food Poisoning?

Food poisoning occurs after consuming food contaminated with germs such as SalmonellaE. coli (Escherichia coli), and Clostridium perfringens. It can also be caused by food containing toxins, human waste, raw meat, and uncooked meals.

Food poisoning is one of the most common reasons for feeling sick, vomiting, and diarrhea. According to the Food and Drug Administration (FDA), it affects 48 million Americans yearly.Trusted Source Only a fraction of that number – 128 thousand – need hospitalization. Even fewer dies because of foodborne illness, which amounts to 3000 death annually. Depending on the harmful substance or organism that contaminated food, the severity of symptoms varies. Fortunately, in most cases, food poisoning can be treated at home.

Food Poisoning: What Is, Food Sources, How To Treat, Causes, and More

Symptoms and causes

Symptoms of food poisoning are not always the same. Their severity and the average time they persist can also differ depending on the source. The most common cause is one of the harmful germs that may contaminate food. See the table below to learn which bacteria cause symptoms of food poisoning and which food sources get contaminated the most often:

Time For Symptoms To DevelopSymptomsName Of The GermFood Sources
30 min – 8 hoursdiarrhea
stomach cramps
feeling nauseous
Staphylococcus aureus (Staph food poisoning)Food that was kept at the wrong temperature (40°F – 140°F) for more than two hours (for instance, puddings, pastries, sliced meat, sandwiches)
Up to 24 hourshigh temperature (fever)
watery diarrhea
stomach cramps
feeling nauseous
VibrioUndercooked or raw shellfish
6 – 24 hoursstomach cramps
vomiting and fever (rarely)
Clostridium perfringensFood kept at the wrong temperature (for instance, meat, gravies, poultry)
6 hours – 6 daysnormal or bloody diarrhea
high temperature
stomach cramps
SalmonellaTrusted SourceUndercooked or raw meats, including chicken and turkey; raw vegetables and fruits; certain animal meat, such as rats, backyard poultry, amphibians, and reptiles; raw juice and milk; eggs
12 – 48 hoursbody aches
high temperature
stomach pain and cramps
feeling nauseous
Norovirusshellfish, leafy greens, fresh fruits, contaminated water
18 – 36 hoursblurry vision
double vision
swallowing problems
difficulty moving eyes
muscle weakness
slurred speech
drooping eyelids
Clostridium botulinum (Botulism)fermented foods, homemade alcohol, food that has been improperly canned
2 – 5 dayshigh temperature
bloody diarrhea
stomach pain and cramps
Campylobacterpets (dogs, cats), raw milk and poultry, contaminated water
3 – 4 dayssevere stomach pain and cramps
bloody diarrhea
hemolytic uremic syndrome (in 5-10% of infected people)
E. coli (Escherichia coli)Trusted Sourceraw vegetables and sprouts, contaminated water, raw milk and juice, raw beef
Up to 1 weekweight loss
stomach cramps
watery diarrhea
feeling nauseous
loss of appetite
increased gass
Cyclosporaherbs, raw vegetables, and fruits
Up to 2 weeksmuscle aches
feeling sick
high temperature
loss of balance
neck stiffness
feeling confused
miscarriage, stillbirth, newborn infection, premature delivery (in pregnant women)
Listeria (invasive illness)soft cheeses, raw sprouts, hot dogs, raw milk, melons, smoked fish, deli meat


Some germ infections originating from food may cause severe long-term health issues, including life-threatening conditions. These include:

DehydrationTrusted Source: Loss of water is the most common complication of food poisoning. It occurs because of diarrhea and vomiting that deprive the body not only of fluids but also essential nutrients such as salts and minerals. Most people can quickly avert dehydration by drinking more fluids, but children, older adults, and people with certain illnesses may be unable to replenish fluids at home. People affected by dehydration sometimes need to go to a hospital to get a proper amount of fluids directly into their bloodstream.

Symptoms of dehydration are easy to spot. They include dizziness, dry mouth, drowsiness, fainting, urinating less than usual, and swollen feet. If severe, it may also lead to severe health issues, including organ damage, kidney failure, swelling of the brain, and seizure.

Pregnancy complications: Certain bacteria responsible for food poisoning may cause pregnancy complications along with typical symptoms of foodborne illness. These may include stillbirth, sepsis or meningitis in the newborn, and miscarriage. 

Systemic diseaseTrusted Source: Contaminated food may sometimes cause a disease affecting various body parts. It is referred to as systemic disease or infection and is usually not observed among younger people. Elders, people who suffer from medical conditions or have weakened immune system, are more at risk of developing this complication of food poisoning. 

The following infections may occur as a result of food poisoning:

Other complications: Rarely, some health problems develop after food poisoning is dealt with:

Food Poisoning: What Is, Food Sources, How To Treat, Causes, and More

Risk factors

Sometimes preventing food poisoning may be impossible, even if the food comes from a reliable source. However, consuming a meal with contaminants or germs does not always result in foodborne illness. Some people are more likely to get food poisonedTrusted Source than others, and these include:

Several risk factors contributing to food poisoning are unrelated to age or health. They refer to how food is handled and whether it is of good or lousy quality. Remember the below risk factors to prevent getting food poisoned:

Diagnosis and tests

Based on the review of symptoms, doctors can usually tell if a person is food poisoned. Questions related to the recently consumed food and drinks, recent travels, and changes in drugs a person takes typically suffice to diagnose food poisoning. However, the reason behind vomiting, diarrhea, and stomach cramps may be unclear. In that case, a doctor may perform a physical exam, review the patient’s medical history, and order additional tests, such as blood and stool tests.

Stool test

A stool test involves delivering a stool sample to a laboratory for testing. A patient who was ordered a stool test need to get a special containerTrusted Source for storing the stool that is available at each pharmacy store. The test can show the presence of bacteria, toxins, parasites, and viruses, which helps rule out health conditions that cause similar symptoms of food poisoning.

Blood test

Blood test helps to determine if a person shows signs of complications from food poisoning like dehydration and various infections. A healthcare professional takes the blood sample, which is then sent to a lab for testing.


Most cases of food poisoning can be treated at home and don’t require any medicationTrusted Source. Symptoms of dehydration are easily treated by replacing fluids and essential minerals that were lost due to vomiting or diarrhea. Over-the-counter medicines may help with stomach cramps and pain, headaches, and flu-like symptoms.

Severe food poisoning, on the other hand, may require medical treatment. If bacteria or parasites cause it, doctors usually prescribe antibiotics or medicines that are effective against parasites (antiparasitics).

Some doctors also recommend probiotics, a type of medicine that contains a variety of live microorganisms whose purpose is to replace beneficial bacteria in the digestive system.

Key facts



July 31, 2023
7 minutes read

Table of Contents

Find a topic by its first letter
Dehydration: What Is, Causes, Symptoms, Signs, and Levels

Dehydration can cause many negative health effects. It is a common problem in children and seniors. Learn how to recognize… read more »

Kidney Infection: What It Is, Symptoms, Treatment, and More
Kidney Infection

Kidney infections are a heterogeneous group of diseases characterized by inflammation of one or both kidneys. What are the symptoms… read more »

Kidney Stones: What Is, Symptoms, Diagnosis, and Treatment
Kidney Stones

Kidney stones can form for a variety of reasons. Learn about factors that increase the risk of kidney stones. See… read more »

Sun Poisoning: What Is, Risk Factors, Symptoms, Diagnosis, and Treatment
Sun Poisoning

Sun Poisoning is a more severe form of sunburn. Additional distressing symptoms may occur. Learn about the effects of sun… read more »

Gastroenteritis: What Is, Symptoms, Causes, and Treatment

Gastroenteritis is a diarrheal disease. Viral infections are a common cause. How to recognize it? How is gastroenteritis treated? read more »

Diarrhea: General Characteristics, Types, Symptoms, Diagnosis, and Effective Treatment

Diarrhea is usually a symptom of a gastrointestinal infection. It is characterized by excessive excretion of stool with a loose… read more »

Listeria: What Is, Causes, Diagnosis, Symptoms, and Treatment

Listeria is a bacterium that can cause infectious disease. You can get infected through food. Find out how to avoid… read more »

Salmonella: What Is, Symptoms, Diagnosis, Treatment and Prevention

Salmonella bacteria infect both humans and animals. They can be found mainly in poultry but also in the meat of… read more »

Norovirus: Symptoms, Causes, and Treatment

Norovirus is a microorganism that can cause symptoms of food poisoning. Learn about treatment methods for viral digestive diseases and… read more »