Banner Health
Making healthcare easier

Food Poisoning

What is food poisoning?

Food poisoning is an illness that happens after you eat food or drink beverages that are contaminated by (contain) harmful bacteria, viruses, parasites, or toxins. It’s common - almost everyone gets food poisoning at least once.

Symptoms of food poisoning depend on exactly what you ate or drank and how your body reacts. You may have nausea, vomiting, diarrhea, stomach cramps and fever.

Many people use the term “food poisoning” for all foodborne illnesses. However, “food poisoning” refers to illness only from food that contains a toxin. “Foodborne illnesses” refers to illnesses from any type of contaminant in food, like an allergen.

What causes food poisoning?

It’s often hard to know exactly which food made you sick. Food poisoning symptoms sometimes start within 30 minutes, but it can also take up to two weeks before you get sick. Occasionally, multiple people eat the same food, but don’t all get sick. It depends on how each person’s body reacts.

There are many different ways foods can get contaminated:

  • Improper food handling
  • Not washing hands before preparing or serving food
  • Not cooking food properly or keeping it hot
  • Not refrigerating food properly
  • Cutting boards, knives or kitchen tools that aren’t washed properly

More than 250 substances, including bacteria, viruses, parasites, toxins, fungi, molds and chemicals can cause food poisoning. Some include:

  • Campylobacter
  • Salmonella
  • Escherichia coli (E. coli)
  • Norovirus
  • Cyclospora
  • Hepatitis A
  • Listeria
  • Rotavirus
  • Astrovirus
  • Sapovirus
  • Bacillus cereus
  • Clostridium botulinum
  • Clostridium perfringens
  • Giardia lamblia
  • Shigella
  • Staphylococcus aureus
  • Vibrio
  • Toxoplasma gondii
  • Cryptosporidium
  • Trichinella
  • Tapeworms, roundworms, flatworms and pinworms

Some foods are more likely to cause food poisoning than others. It’s a good idea to be especially careful with:

  • Raw or undercooked meats, poultry, eggs and seafood
  • Unpasteurized (raw) dairy products and juices
  • Fresh fruits and vegetables
  • Meat spreads and pâtés
  • Uncooked deli meats and hot dogs
  • Raw flour
  • Soft cheeses, such as brie, camembert, and certain Mexican-style cheeses 

Soft cheeses and unpasteurized milk can harbor harmful bacteria such as listeria, E. coli, campylobacter, and salmonella if not properly handled or stored. Pregnant women are advised to avoid soft cheeses due to the risk of listeria infection, which can be dangerous for both mother and baby. Similarly, consuming unpasteurized dairy products poses a higher risk of foodborne illness, particularly for children, pregnant women and individuals with weakened immune systems.

How can you prevent food poisoning?

Food can be contaminated at any stage, including processing, storage and preparation. To lower your risk of food poisoning, you should:

  • Wash your hands before preparing food, and anytime you’ve handled raw or undercooked meat, poultry or seafood
  • Wash fruits and vegetables
  • Cook foods properly – heat kills most germs that cause food poisoning 
  • Keep hot foods hot and cold foods cold
  • Avoid cross-contamination in the kitchen (such as cutting vegetables on the same surface where you cut meat)
  • Be careful with expired foods
  • Avoid damaged foods
  • Get rid of moldy foods
  • Check restaurant health ratings
  • Choose restaurants that look and smell clean
  • Return or destroy any recalled foods
  • If you work in food service, be mindful of food-handling practices

Is food poisoning contagious?

Some types of food poisoning are contagious (can be passed from person to person). It depends on what’s causing the infection. Certain germs can survive on hands or surfaces and spread to other people. If someone with food poisoning prepares food in a restaurant, grocery store or home kitchen, they could contaminate the food they are making.

What are the symptoms of food poisoning?

Your symptoms can vary depending on what you ate and how it’s affecting your body. Common symptoms of food poisoning include:

  • Nausea or vomiting
  • Diarrhea (possibly with blood in it)
  • Stomach cramps or stomach pain
  • Loss of appetite
  • Headache
  • Fever
  • Chills 
  • Muscle aches
  • Weakness or fatigue

Some dangerous types of food poisoning can affect the nervous system. In that case, you may have:

  • Blurry vision or double vision
  • Trouble swallowing
  • A change in the way your voice sounds
  • Trouble moving your arms and legs
  • Tingling or numbness
  • Headache
  • Weakness

Is it the stomach flu or food poisoning?

The stomach flu (gastroenteritis) and food poisoning can have the same symptoms. Many of the same viruses, bacteria, toxins and parasites can cause stomach flu and food poisoning – the only difference is the source. If you became infected from food, it’s food poisoning. If you became infected from something else, it’s stomach flu.

If you think you have food poisoning but aren’t sure where you got it, there is a good chance it is the stomach flu. It is possible that something infected you when you touched a contaminated surface or were swimming or exposed to outdoor water. You can also be infected by animals.

How can you treat food poisoning?

Most of the time, you can treat food poisoning at home. You should feel better within a few days, and sometimes it clears up within hours. If you’re vomiting, have diarrhea or have a fever, you can lose a lot of water. It’s important to prevent dehydration. Stay hydrated by sucking on ice chips or taking small sips of fluids. Good choices are:

  • Water
  • Broth
  • Diluted juice
  • Sports drinks
  • Coconut water
  • Rehydration fluids (such as Pedialyte)
  • Herbal teas made from mint, chamomile or dandelion (which can soothe your stomach)

You’ll want to get plenty of rest and gradually introduce small portions of bland foods when you feel ready to eat. Start with things like:

  • Toast
  • Bananas
  • Crackers
  • Oatmeal
  • Rice 
  • Jell-O or other gelatin dessert

Avoid fizzy drinks, fatty foods, spicy or strongly flavored foods, dairy, caffeine, alcohol and nicotine. Take a break from eating if your symptoms return.

Some over-the-counter (OTC) medications can help with your symptoms. Loperamide (Imodium A-D) can treat diarrhea and bismuth subsalicylate (Pepto-Bismol) can help with nausea and vomiting. You’ll want to talk to a health care provider or pharmacist for help on using these medications since vomiting and diarrhea are your body’s ways of getting the contaminants out. These medications aren’t recommended for children.

As you return to a regular diet, be sure to practice good food hygiene habits and be cautious about your food choices. That will help reduce the odds that you get food poisoning again. 

When should you see a doctor?

Sometimes, food poisoning can cause serious complications. If your food poisoning symptoms are severe or last more than a few days, contact a health care provider. 

For children, contact your pediatrician if your child has:

  • Signs of dehydration such as excessive thirst, little or dark urine, dry mouth, weakness or dizziness
  • Frequent vomiting, where they can’t keep liquids down
  • Diarrhea that lasts more than a day
  • Stools that are black, tarry, bloody or contain pus
  • Behavior changes
  • Severe pain
  • Any fever in children under age 2, or fever of 102 F or higher in older children

For adults, contact your primary care provider if you have:

  • Signs of dehydration such as excessive thirst, little or dark urine, dry mouth, weakness or dizziness
  • Symptoms that affect your nervous system (such as blurry vision, muscle weakness or skin tingling)
  • A fever of 102 F or higher
  • Diarrhea lasting more than three days
  • Bloody stools
  • Frequent vomiting, where you can’t keep liquids down
  • Changes in your behavior or thinking

These people should be especially cautious and seek medical advice promptly. They are more likely to get food poisoning and more likely to develop complications:

  • People who have weakened immune systems
  • Pregnant women
  • People with chronic illnesses
  • Young children under age 5
  • Adults aged 65 or older 

How is food poisoning diagnosed and treated?

To diagnose food poisoning, your provider will likely ask you about your symptoms, what you’ve recently eaten, symptoms in other people near you, any medication changes and any recent travel (you may be more likely to be infected outside the United States). They may want you to have your blood or stool tested. They may also test your urine to see if you’re dehydrated.

Your provider might recommend fluids, antibiotics or antiparasitics to fight the infection or probiotics to help increase the good bacteria in your digestive tract. In severe cases, especially with dehydration, you may need hospitalization and intravenous (IV) fluids.

Does food poisoning cause complications?

While food poisoning usually goes away without complications, in rare cases it can cause more serious, long-term problems such as:

  • Blood clots that form in the kidneys
  • Hemolytic uremic syndrome, which can cause kidney failure
  • Bacteria that spreads to the bloodstream
  • Sepsis, which is a condition where your immune system damages your body
  • Meningitis, which is swelling that can affect the brain and spinal cord
  • Brain damage
  • Nerve damage
  • Pregnancy complications
  • Guillain-Barré syndrome (GBS)
  • Irritable bowel syndrome (IBS)
  • Arthritis
  • Difficulty breathing

Should you report food poisoning?

If you think you got food poisoning from a restaurant, grocery store or other food establishment, you should report it to your local health department. According to the Centers for Disease Control and Prevention (CDC), you should report it even if you don’t know what made you sick. Reporting can help officials identify an outbreak, notify the public and take steps to stop it.

If you think you or someone in your family may have a case of food poisoning and you’re concerned about the symptoms, visit a Banner Urgent Care near you for advice and help.