Food poisoning - Symptoms of food poisoning

The length of time it takes for the symptoms of food poisoning to develop will vary depending on the type of bacteria involved and how much contaminated food is eaten.

The incubation period (the time between eating contaminated food and the onset of symptoms) can be as short as a few hours or as long as several weeks.

The most common symptoms of food poisoning are:

Vomiting usually only lasts for a day or so, but it can sometimes last longer. Diarrhoea will often last for a few days, although you may continue to have an upset stomach for about a week or so.

Other symptoms of food poisoning include:

stomach cramps
abdominal pain
loss of appetite
a high temperature of 38°C (100.4°F) or above
muscle pain
chills

Most people make a full recovery 1-2 days after the onset of symptoms.

When to seek medical advice

Most cases of food poisoning do not require medical treatment. However, you should seek medical advice if you have any of the following signs or symptoms:

vomiting that lasts more than two days
you are unable to keep liquids down for more than a day
diarrhoea that lasts for more than three days
blood in your vomit
blood in your stools
seizures (fits)
changes in your mental state, such as confusion
double vision
slurred speech
signs of severe dehydration, such as a dry mouth, sunken eyes and an inability to pass urine, or passing small amounts of dark, strong-smelling urine

Pregnancy

Always contact your GP if you get food poisoning during pregnancy. Extra precautions may be needed.