Foodborne Illness
Medically reviewed by Drugs.com. Last updated on Apr 6, 2025.
What is a foodborne illness?
A foodborne illness is any illness that develops after you have contaminated food or liquid. The food or liquid may be contaminated with bacteria, a virus, a toxin, or a parasite. Meat, seafood, produce, and dairy products are common foods that can become contaminated. Examples of foodborne illness include E. coli infection, hepatitis A, and shigellosis.
What may cause a foodborne illness?
- Infection means the food or liquid contained a live germ, such as bacteria or a virus. The germ grows in your intestines and causes symptoms. An example is norovirus. Symptoms develop as the norovirus reproduces and grows in the intestines.
- Food poisoning means the food or liquid contains a toxin produced by a germ or other harmful substance. An example is botulism. Symptoms develop from a reaction to the toxin produced by botulinum bacteria, not to the bacteria. Toxins can be in something you eat or drink, even if the germ or substance is not. Food poisoning most commonly happens because of raw or undercooked food.
What are the signs and symptoms of a foodborne illness?
- Nausea and vomiting or an upset stomach
- Abdominal cramps or tenderness
- Dehydration or diarrhea that may be watery or bloody
- Multiple bowel movements with blood, mucus, or pus
- Dry mouth, trouble swallowing or speaking
- Facial weakness
- Blurred or double vision, or drooping eyelids
- Trouble breathing
- Fever
How is a foodborne illness diagnosed?
Your healthcare provider will ask about your symptoms and the foods you have eaten recently. Your provider will ask when you last ate, and where you were. Your provider may want to know if anyone who ate with you is also sick. Your provider will examine your abdomen and check for signs of dehydration. Dehydration can happen if you have diarrhea or are vomiting. You may also need the following:
- A bowel movement culture may show which germ is causing your food poisoning.
- Blood tests check for bacteria or viruses that can cause food poisoning. They may also show if you are dehydrated or have signs of infection or inflammation.
How is a foodborne illness treated?
Treatment depends on the cause of the illness and how severe your symptoms become:
- IV fluids may be given if you become severely dehydrated.
- Antibiotics may be given if your immune system is too weak to fight the infection.
- Antitoxin medicine may be given to help stop the spread of a toxin, such as botulism.
How can I manage a foodborne illness?
- Drink liquids as directed. Ask your healthcare provider how much liquid to drink each day, and which liquids are best for you. You may also need to drink an oral rehydration solution (ORS). An ORS has the right amounts of sugar, salt, and minerals in water to replace body fluids.
- Eat bland foods. When you feel hungry, begin eating soft, bland foods. Examples are bananas, clear soup, potatoes, and applesauce. Do not have dairy products, alcohol, sugary drinks, or drinks with caffeine until you feel better. Avoid eating high-fat or fast foods.
- Eat small meals throughout the day. Your stomach may tolerate small meals every 2 to 3 hours instead of 3 large meals.
- Ask your provider before you take medicines to stop your diarrhea. This may make the infection last longer or cause other side effects.
- Rest as much as possible. Slowly start to do more each day when you begin to feel better.
How can I prevent a foodborne illness?
- Wash your hands often. Wash your hands with soap and water several times each day. Wash before you prepare or eat food, and after you use the bathroom or change a child's diaper. Wash for at least 20 seconds. Rinse with warm, running water for several seconds. Then dry your hands with a clean towel or paper towel. Use hand sanitizer that contains alcohol if soap and water are not available.
- Prepare food safely. Keep raw meat, seafood, and eggs separate. Keep these away from other kinds of foods, such as fruits and vegetables. If possible, use separate cutting boards and knives for each kind of food. You can also wash cutting boards, cutting utensils, and dishes as you go. Use hot water and dish soap to wash items. Rinse each item under running water. Do not put food on any unwashed dish that raw meat, seafood, or eggs were on.
- Cook food all the way through. Cook eggs until the yolks are firm. Use a meat thermometer to make sure meat is heated to a temperature that will kill bacteria. Do not eat raw or undercooked chicken, turkey, seafood, or beef.
- Store food properly. Refrigerate or freeze cooked foods and leftovers. Store raw and cooked foods separately.
- Learn safe canning methods if you can food at home. Boil any food that has been canned or vacuum packaged at home. Boil it at 176°F (80°C) for 30 minutes or at 212°F (100°C) for 10 minutes.
- Be aware when you camp or travel. Drink only clean water. Do not drink from rivers or lakes unless you purify or boil the water first. When you travel, drink bottled water. Do not add ice. Do not eat fruit that has not been peeled. Do not eat raw fish or meat that is not fully cooked.
- Limit contact with others while you have symptoms. Some types of foodborne illness can spread to others. Avoid close contact with others until your symptoms are gone, or as directed. Do not swim in public pools or go to work or school until you have had no diarrhea for 1 day.
Call your local emergency number (911 in the US) or have someone call if:
- You have a seizure.
- You have chest pain.
- You have trouble breathing.
When should I seek immediate care?
- You see blood in your vomit or diarrhea.
- You feel like you are going to faint.
- You have severe abdominal pain.
- Your abdomen is hard and swollen, and you are constipated.
- You have black or bright red bowel movements.
- You have severe nausea and are vomiting.
- Your mouth is dry, your lips are cracked, and you are thirsty.
- You are urinating less than usual or not at all.
- Your heartbeat or breathing is faster than usual.
When should I call my doctor?
- You have a fever.
- Your diarrhea or vomiting gets worse.
- You have questions or concerns about your condition or care.
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