Food Poisoning Symptoms — Continued
Dangerous signs of food poisoning
For some people, food poisoning can lead to hospitalization or even be life-threatening. Young children, the elderly, pregnant women, and people with weak immune systems are especially at risk for complications from food poisoning.
If symptoms are severe enough, anyone can be in danger from food poisoning. Dangerous symptoms include:
- Fever over 101.5° F
- Blood in stools or bloody diarrhea
- Inability to keep down liquids
- Lack of urination, dry mouth, dizziness, or other signs of dehydration
- Symptoms lasting for longer than three days
In young children with food poisoning, look for high fever, excessive fussiness or sleepiness, or signs of dehydration, such as:
- Lack of tears when crying
- No wet diapers for three or more hours
- Sunken eyes, cheeks, or soft spot in the skull
If you notice any of those dangerous symptoms in adults or children, seek emergency medical care as quickly as possible.
Some forms of food poisoning, such as botulism, are always dangerous. Botulism, which can affect your nervous system, usually occurs from foods that are improperly canned or fermented at home.
Symptoms of food poisoning from botulism include:
- Muscle weakness
- Severe headache or dizziness
- Blurred or double vision
- Drooping eyelids
- Dry mouth
- Slurred speech
- Difficulty swallowing
- Feeling of a thick tongue
- Tingling or numbness in skin or limbs
If botulism is left untreated, it can cause muscle paralysis and organ failure. If you experience symptoms of botulism, go to an emergency room immediately.
How long does food poisoning last?
How long food poisoning lasts depends on the bacteria or virus that causes it.
Staphylococcal food poisoning, caused by staph bacteria, starts quickly. Symptoms can begin 30 minutes to six hours after you eat contaminated food and resolve after a day or two.
Another common type of food poisoning is salmonella, which usually starts 12 to 72 hours after you are infected. Symptoms of salmonella usually last a week or less.
Food poisoning from Clostridium perfringens is one of the most common types of food poisoning, and it causes only diarrhea, not vomiting. The symptoms usually begin eight to 10 hours after you eat contaminated food and end in 24 hours.
If you are exposed to norovirus through contaminated food, you will usually become ill in 12 to 48 hours. Symptoms generally last one to three days.
Food poisoning from E. coli bacteria can take longer to develop. You may notice symptoms in as few as one or as many as 10 days, though three to four days is common. E. coli food poisoning usually resolves after five to seven days.
In general, food poisoning progresses quickly. If your symptoms last more than a few days, you should see a doctor.
Updated:  
June 28, 2023
Reviewed By:  
Janet O’Dell, RN