Food poisoning can be caused by toxins or microorganisms in food or drinks. Symptoms may include vomiting, diarrhea, fever, and more.

Food poisoning is extremely common, affecting an estimated 9.4 million Americans yearly (1).

Food poisoning can be caused by bacteria-contaminated foods or by eating foods containing poisonous toxins, such as certain mushroom species (2, 3).

Symptoms and severity vary, and it could take hours to days for them to appear (4), making identifying the offending food quite difficult.

High risk foods include undercooked meat/chicken, eggs, unpasteurized dairy products, shellfish, and unwashed fruits/veggies (5).

This article lists 10 symptoms of food poisoning and what you should do if you think you have it.

1. Abdominal pain and cramps

Abdominal pain caused by food poisoning is felt around the trunk of your body. Harmful toxins irritate your stomach lining, causing cramping that is worsened when your abdominal muscles work to get rid of the organisms (6, 7).

However, abdominal pain and cramps may be caused by other things than food poisoning. Because of this, these symptoms alone may not be a sign of food poisoning (8).

Furthermore, not all cases of food poisoning will result in abdominal pain or cramps.


Abdominal pain and cramps can indicate inflammation in your stomach and intestines. Cramping may also occur as your body tries to eliminate harmful organisms.

2. Diarrhea

Diarrhea is watery and loose stools occurring three or more times in a 24-hour period, and it’s often caused by food poisoning. It’s usually accompanied by an urgent feeling for the bathroom and bloating/abdominal cramps (9).

Diarrhea occurs as inflammation makes your bowel less effective at reabsorbing the water and other fluids it secretes during digestion (10).

This means it raises your chance of becoming dehydrated. Make sure to drink fluids such as water or broth and check that urine color is light yellow to clear (11).


Diarrhea consists of three or more loose, watery stools in 24 hours. The biggest health risk of diarrhea is dehydration, so it’s important to drink enough fluids.

3. Headaches

Headaches are extremely common (12). Stress, alcohol, dehydration, and fatigue can all be causes (13, 14, 15).

Food poisoning may also lead to a headache, as it can cause both fatigue and dehydration. Vomiting and diarrhea also increase your chance of dehydration-related headaches (16).


You may get a headache when you have food poisoning, especially if you become dehydrated.

4. Vomiting

Vomiting is a natural response to food poisoning. It happens when your body tries to expel harmful organisms or toxins.

Some experience projectile vomiting that subsides quickly, while others vomit intermittently for several days. If you can’t keep fluids down, seek medical help to avoid dehydration (17).


Many people with food poisoning vomit. It’s a protective mechanism that helps your body remove harmful organisms you have eaten.

5. Generally feeling sick

Food poisoning often causes loss of appetite and fatigue as your immune system responds to the infection (18).

Your body releases chemical messengers called cytokines, which have many different roles.

These include regulating your body’s immune response and signaling to the brain to trigger the symptoms we generally associate with illness (19, 20)

This collection of symptoms can result in what is sometimes called “sickness behavior,” as you withdraw from social interactions, rest and stop eating.

It’s a sign that your body is diverting its attention from other body processes like digestion to prioritize fighting an infection (21).


Cytokines are chemical messengers that are important in regulating your immune response. Their presence also causes some of the typical symptoms of illness, such as loss of appetite.

6. Fever

A fever is when your body temperature rises above 97.6–99.6°F (36–37°C). Fevers occur as part of your body’s natural defense against infection.

Fever-producing substances called pyrogens are released by your immune system or by the invading bacteria. They trigger a rise in temperature by making your brain think you’re colder than you really are.

This helps boost the activity of white blood cells as they fight the infection (22).


Fever is a common symptom of illness. It helps fight infection by making your body too hot, which helps your immune system fight infection.

7. Chills

Chills can occur as your body shivers to raise your temperature.

These shivers result from your muscles rapidly contracting and relaxing, which generates heat. They often accompany a fever, as pyrogens trick your body into thinking it’s cold and need to warm up (23).

A fever can occur with many different illnesses, including food poisoning, making chills one of its common symptoms.


Chills often accompany a fever, which can occur in cases of food poisoning. Thinking it’s too cold, your body shivers in an attempt to warm up.

8. Weakness and fatigue

Feeling weak or tired can be a symptom of food poisoning, partly due to the release of chemical messengers called cytokines (24).

These symptoms are also signs of sickness behavior, which helps you rest and recover. If you experience this, it is best to listen to your body and rest.


Weakness and fatigue are common side effects of food poisoning caused by chemical messengers called cytokines released by your body when you are sick.

9. Nausea

Nausea is how you feel when you’re about to vomit. It can be caused by things like food poisoning, migraine, or motion sickness (25).

In case of an infection, it is a warning sign that you may have eaten something harmful.

If you feel nauseous, you might want to try some of these natural remedies to help relieve your symptoms.


Nausea is the debilitating feeling of being queasy before you are sick. It serves as a warning signal of food poisoning.

10. Muscle aches

When you get an infection, like food poisoning, you can get muscle pain. This happens because your body releases histamine to widen your blood vessels and allow your white blood cells to fight the infection (26).

Cytokines and other substances involved in the immune response can reach other parts of your body, triggering pain receptors and causing aching.


An infection like food poisoning can make your body ache due to inflammation caused by the immune system’s response.

To prevent food poisoning, it’s a good idea to practice good hygiene in the kitchen and wash your hands.

Most cases of food poisoning are not serious and will subside on their own. If symptoms linger, it’s best to rest, stay hydrated, and see a doctor if symptoms don’t improve in a few days.