Food poisoning

We get food poisoning from eating food that contains harmful bacteria, viruses or poisonous substances known as toxins.


The symptoms of food poisoning can vary, depending on what has caused it.

Common symptoms include:

  • nausea
  • vomiting
  • stomach pains
  • diarrhoea
  • headaches
  • fever (sometimes)

Symptoms usually only last a few days. But occasionally, food poisoning can be very serious and even cause death. So it's important to prevent food poisoning with good food hygiene.

How it happens

When someone swallows bacteria that cause food poisoning, there is a delay (incubation period) before symptoms begin. This is because most bacteria that cause food poisoning need time to multiply in the intestine.

The length of the incubation period depends on the type of bacteria and how many are swallowed. It could be hours or days. This means that it may not have been the last meal you ate that caused the food poisoning symptoms.

What you should do

There are three main things to consider when you have food poisoning:

  1. rehydration - drink plenty of fluids and perhaps use rehydration powders available from pharmacies
  2. medical assistance - if you are concerned about your health or the health of someone else, contact NHS Direct (111) or your GP for advice (especially in the case of pregnant women, elderly people, children and people who are already ill)
  3. reporting - if you think that your illness was caused by food prepared outside the home, email us. We will ask if you have a stool sample result confirming you have suffered from a food poisoning organism, so consider contacting your GP for a sample to be taken as soon as you can. We may need to investigate to ensure no one else is at risk from food poisoning and knowing which organism has made you ill will facilitate the investigation. 

If you have food poisoning symptoms and handle food as part of your job

If you are a food handler you must not prepare food if you have food poisoning symptoms. 

You must tell your employer immediately.

You must then wait for at least 48 hours after symptoms have cleared up before being allowed anywhere in the business where you might contaminate food.

Email: for further information.

More information about food practice is available on the Food Standards Agency website.

Avoiding food poisoning

You can minimise your chances of suffering from food poisoning.


Wash your hand regularly using soap and hot water and in particular after visiting the toilet, handing raw foods and before touching ready to eat foods.


Proper cooking kills food poisoning bacteria such as listeria, salmonella, E.coli 0157 and campylobacter. Cook food thoroughly, especially meat; don’t just rely on cooking times on labels always check food and where meat is concerned ensure that juices run clear. Food should be piping hot all the way through so check the thickest part of the food.

If you reheat food make the same checks all over again, and don’t reheat it more than once.


It is very important to keep certain foods at the right temperature to prevent bacteria growing or toxins forming. Always check the label on food packaging to make sure you are storing it correctly; foods kept at room temperature that should be chilled will quickly grow bacteria, which will multiply to dangerous levels.

Any cooked leftovers should be cooled quickly and then stored in the fridge or freezer. To speed up the process separate the food in to smaller portions.

Cross contamination

Cross Contamination is the transfer of bacteria from foods (usually raw) to other foods. Bacteria can be transferred by hands, equipment, work surfaces or other utensils that come into contact with the food.

In particular you should ensure that you wash your hands after touching raw foods, keep your raw and ready to eat foods separate and use different chopping boards and utensils for raw and cooked foods, which you should clean thoroughly after use.

When storing food in the fridge make sure your raw meat is in sealable containers at the bottom of the fridge where it cannot drip onto other foods.

Contact Commercial Services

0300 123 5015

Page last reviewed: 31 January 2024