“Food poisoning” is a broad term that can actually cover a whole lot of different infections.
Your exact symptoms and how bad they are will vary. They will depend on the kind of bacteria, virus, or parasite that’s infected you, how much is in your system, and how well your immune system is fighting it off.
Despite the wide range of types, most cases of food poisoning cause some mix of the following:
If you have a mild case, you might think you have a “stomach flu” or virus. You may get better without any treatment. But some people have such bad symptoms that they may need to go to the hospital.
Common Food Poisoning Symptoms
Cramps in your stomach and gut, diarrhea, and vomiting may start as early as 1 hour after eating tainted food and as late as 10 days or longer. It depends on what is causing the infection.
Some other possible, common symptoms of a variety of food poisonings might include:
Symptoms of Food Poisoning That Could Be Life-Threatening
Some symptoms mean you should seek medical help immediately:
- Repeated vomiting; not being able to hold anything down
- Signs of dehydration: dry mouth, little or no urination, dizziness, or sunken eyes
- Any diarrhea in a newborn or infant
- Diarrhea that lasts longer than 2 days (1 day in a child) or is severe
- Severe gut pain
- Fever of 102 F or higher, or a rectal temperature of 100.4 F in a baby younger than 3 months
- Black, tarry, or bloody stools
- Muscle weakness
- Tingling in your arms
- Blurry vision
- Diarrhea or flulike illness in pregnant women
- Jaundice (yellow skin), which can be a sign of hepatitis A
Food Poisoning Causes
You’ve probably heard of the some of the bad bugs that can cause food poisoning:
- E. coli
Botulism is a rare but severe type of bacterial food poisoning.
Clostridium botulinum is the bacteria that causes botulism. It grows on food that hasn’t been cooked or stored at the right temperatures to kill it or stop it from growing. This sometimes happens with foods that have been canned at home. Babies can get it from foods that have bacteria in them, because they don’t have the natural defenses that older children and adults do. Honey is the most common food that can infect a baby with botulism -- never give it to a baby under 1 year of age.
Symptoms might include:
- Slurred speech or blurred vision
- Muscle weakness
- Hard time swallowing
- Dry mouth
- Muscle paralysis from the head down through the body
Call 911 if you see any symptoms of botulism in yourself or a loved one.
Food Poisoning Risk Factors
Anyone who eats contaminated food can get ill from food poisoning. But just how sick you get depends on what the infection is, how much of it you’re exposed to, your age, and your health. Certain groups of people have a greater chance of getting seriously sick from food poisoning:
- Adults ages 65 and older: As you age, your immune system becomes less able to fight off infection.
- Babies and young children: Very young people don’t have fully developed immune systems.
- Pregnant women: Changes in your body when you’re pregnant make it more likely that germs and bacteria can make you seriously sick.
- People with long-term illnesses: Conditions such as diabetes, kidney disease, liver disease, HIV, AIDS, or treatment for cancer can weaken your immune system.
Food Poisoning Diagnosis
To diagnose food poisoning, your doctor will review your medical history, including your symptoms, how long you’ve had them, and what foods you’ve eaten. They’ll also ask whether you’ve traveled, and they may ask whether anyone else at home has these symptoms.
Based on what they find out, they may test your urine to see if you’re dehydrated. They may also take blood and stool samples to try and trace the organism that has caused your illness.
If they find out the organism, they may contact your local health department to see if there’s an outbreak. It’s not always possible to find the exact cause.
Viral Gastroenteritis (‘Stomach Flu’)
Viral gastroenteritis, or “stomach flu,” has several symptoms that are a lot like those of food poisoning, including:
- Stomach pain and cramping
- Watery diarrhea
- Nausea and vomiting
Just like with food poisoning, you may have a fever. But it will be a low-grade one (less than 101 F). Your head and muscles could also hurt.
These symptoms often start within 1 to 3 days of when you catch the infection. They usually last just a day or 2, but can go on as long as 10 days.
When Should I Call a Doctor?
A mild case of food poisoning usually passes on its own with just rest and lots of fluids. But if you or a loved one has any signs of botulism or life-threatening illness, call 911 right away.