NHS
Food poisoning is an illness caused by eating contaminated food. Most people get better without the need for treatment.
In most cases, food that causes food poisoning is contaminated by bacteria, such as salmonella or Escherichia coli (E. coli), or a virus, such as the norovirus.
The symptoms of food poisoning usually begin 1-3 days after eating contaminated food. They include:
- feeling sick
- vomiting
- diarrhoea
- stomach cramps
Some toxins can cause food poisoning within a much shorter time. In these cases, vomiting is the main symptom.
Foods particularly susceptible to contamination if not handled, stored or cooked properly include:
- raw meat and poultry
- raw eggs
- raw shellfish
- unpasteurised milk
- ‘ready to eat’ foods, such as cooked sliced meats, pâté, soft cheeses and pre-packed sandwiches
How is food contaminated?
Food can become contaminated at any stage during production, processing or cooking. For example, food poisoning can be caused by:
- not cooking food thoroughly (particularly poultry, pork, burgers, sausages and kebabs)
- not storing food that needs to be chilled at below 5°C correctly
- leaving cooked food for too long at warm temperatures
- someone who is ill or who has dirty hands touching the food
- eating food that has passed its ‘use by’ date
- cross-contamination (the spread of bacteria, such as E. coli, from contaminated foods)
Read more about the causes of food poisoning.
