TL;DR:
Most cases of food poisoning get better with rest, fluids, and time. The biggest concern is dehydration, so replacing lost fluids is important. However, severe vomiting or diarrhea, blood in the stool, a high fever, confusion, fainting, or signs of serious dehydration may mean it’s time to seek medical care. Babies, older adults, pregnant people, and those with weakened immune systems may need medical attention sooner.
Food poisoning is an illness caused by eating or drinking something contaminated with harmful germs, toxins, or harmful chemicals. The most common symptoms of food poisoning are nausea, vomiting, diarrhea, fever, and stomach cramps.
In most cases, food poisoning is mild and resolves within a few days. Treatment for routine food poisoning consists of rest and staying hydrated. However, some cases of food poisoning can be severe enough that they require medical attention.
What Causes Food Poisoning?
Food poisoning can have several different causes.
Bacterial Food Poisoning
Bacteria are among the most common causes of foodborne illness. Examples include:
- Salmonella
- E. coli
- Campylobacter
- Staphylococcus aureus
- Listeria
Food can be contaminated with these bacteria when undercooked, stored at unsafe temperatures, or handled improperly.
Viral Food Poisoning
Viruses can spread through contaminated food, water, contact with surfaces, or infected food handlers. Norovirus is a common example and often causes sudden vomiting and diarrhea.
Parasitic Food Poisoning
Parasites can enter the body through contaminated food or water, and may be microscopic or visible. Usually, these appear in uncooked meat and fish, but can spread through unwashed produce as well. These illnesses may sometimes last longer than typical viral or bacterial food poisoning.
Foodborne Toxins
Certain bacteria produce toxins in food. Poisonous mushrooms, contaminated seafood, and other naturally occurring toxins can also cause food poisoning. Like other types of food poisoning, they can occur due to poor storage and care.
Some toxin-related illnesses can become serious very quickly.
Common Symptoms
While many cases of food poisoning become show symptoms within a few hours of eating contaminated food, other cases can take days for symptoms to appear.
Common symptoms include:
- Nausea
- Vomiting
- Watery diarrhea
- Stomach cramps
- Abdominal pain
- Loss of appetite
- Mild fever
- Headache
- Fatigue or weakness
- Dehydration (secondary to vomiting and diarrhea)
Watch for Signs of Dehydration
Vomiting and diarrhea can cause the body to lose water and electrolytes quickly, causing dehydration.
Signs of dehydration include:
- Dry mouth
- Extreme thirst
- Dark-colored urine
- Urinating less often
- Dizziness or lightheadedness
- Weakness
- Feeling unusually tired
Severe dehydration can be dangerous and may require treatment with intravenous fluids.
What to Do for Food Poisoning
Most mild cases can be safely treated at home. In these cases, it’s a matter of treating the symptoms as the food poisoning resolves itself.
Replace Lost Fluids
Make sure you stay hydrated, .
Drink:
- Water
- Oral rehydration solutions
- Clear broth
- Electrolyte drinks
If you are nauseated or vomiting, take small, frequent sips instead of trying to drink a lot at once.
Don’t drink alcohol, which can worsen dehydration.
Also, avoid caffeine. Not only is caffeine a mild diuretic, meaning it can cause you to have to urinate more, but it can aggravate your digestive system.
Eat When You Feel Ready
Don’t force yourself to eat if you’re still dealing with vomiting. Once you feel well enough, start with small portions of simple foods such as:
- Toast
- Crackers
- Rice
- Bananas
- Applesauce
- Potatoes
- Soup
Gradually return to your normal diet as you begin feeling better. Avoid foods that are greasy or spicy for a few days, as they can be more difficult to digest.
Over-the-Counter Treatments
Some over-the-counter medications can help manage symptoms, but they should be used carefully.
Bismuth Subsalicylate
It’s more commonly known by the brand name Pepto-Bismol, and may help relieve:
- Diarrhea
- Nausea
- Upset stomach
- Abdominal discomfort
Follow the package directions carefully.
People who are allergic to aspirin, take certain blood-thinning medications, have ulcers or other conditions should check with a doctor before taking bismuth subsalicylate.
Loperamide
Loperamide can reduce diarrhea by slowing movement through the intestines. However, it should not be used in every case.
Avoid loperamide if you have:
- Bloody diarrhea
- A significant fever
- Severe abdominal pain
- Suspected serious bacterial food poisoning
In some cases, reducing diarrhea slows down the body’s ability to flush out the harmful bacteria.
Pain and Fever Relief
Acetaminophen may help relieve mild fever, headache, or body aches. Always follow label directions and avoid taking more than the recommended dose.
What Not to Do
If you have suspected food poisoning:
- Do not take leftover antibiotics.
- Do not take someone else’s prescription medication.
- Do not force yourself to eat while actively vomiting.
- Do not ignore signs of dehydration.
- Do not prepare food for others while you are sick.
- Do not assume anti-diarrheal medicine is always appropriate.
Antibiotics do not treat viral food poisoning and are unnecessary for many bacterial infections. Some types of bacterial food poisoning can even become more dangerous if treated incorrectly.
Only take antibiotics when prescribed by a healthcare professional.
When to Contact a Doctor
Seek medical advice if symptoms are severe, worsening, or not improving.
Contact a healthcare professional if you have:
- Diarrhea lasting more than several days
- Frequent vomiting that prevents you from keeping fluids down
- Blood in your stool
- Black or tarry stool
- High or persistent fever
- Severe abdominal pain
- Significant dizziness or weakness
- Signs of dehydration
- Symptoms that improve and then suddenly worsen
Young children, older adults, pregnant people, and people with weakened immune systems or serious chronic medical conditions are at greater risk of complications and may need medical attention sooner.
When to Call 911
Some symptoms may indicate severe dehydration, poisoning, or another medical emergency.
Call 911 or seek emergency medical care for:
- Difficulty breathing
- Fainting
- Confusion
- Seizures
- Extreme weakness
- Severe dehydration
- Difficulty speaking
- Difficulty swallowing
- Muscle weakness or paralysis
- Vomiting blood
- Severe or rapidly worsening abdominal pain
- Signs of shock
Symptoms involving the nervous system, such as blurred vision, muscle weakness, difficulty swallowing, or trouble breathing, can indicate exposure to a dangerous toxin and require immediate medical attention. Be prepared for an emergency by taking a first aid course.
Most Cases Improve With Supportive Care
Most food poisoning improves with rest, fluids, and time. Preventing dehydration should be the main priority.
Over-the-counter medications may help control some symptoms, but they are not appropriate in every situation. Bloody diarrhea, persistent vomiting, high fever, severe abdominal pain, neurological symptoms, or signs of dehydration should always be taken seriously.
If symptoms are severe or you are unsure whether someone can safely recover at home, contact a healthcare professional.