Food poisoning

Food poisoning is an illness caused by eating contaminated food. It’s not usually serious and most people get better within a few days without treatment. In most cases of food poisoning, the food is contaminated by bacteria, such as salmonella or Escherichia coli (E. coli), or a virus, such as the norovirus.


Typical symptoms of food poisoning are diarrhea and vomiting – the body’s way of managing the problem. Symptoms usually pass in a few days without treatment. However, if food poisoning has been caused by parasites and toxins, such as poisonous mushrooms, urgent medical care is required


Food poisoning is often caused by food (or drink) that has not been correctly stored or cooked, allowing bacteria and viruses to thrive. The food may then become contaminated with Escherichia coli, listeria, campylobacter, or salmonella bacteria – or norovirus. Toxins found in soil surrounding rice and vegetables which have not been properly washed can also cause food poisoning, as can parasites, chemicals and poisons.


Common causes of food poisoning:


  • Incorrectly stored food
  • Undercooked food
  • Contaminated water or food cooked in contaminated water
  • Food containing bacteria
  • Infected people who have touched food
  • Poor hygiene.


The symptoms of food poisoning usually begin quickly, often within a few hours. In some cases, the incubation period can be longer – sometimes it takes several days before you become ill. The most common symptoms are diarrhea, nausea and vomiting, though many also experience abdominal pain and fever.  You should pay attention to your general condition and watch for signs of severe dehydration. Children can suffer more severely from dehydration than adults.


Bear in mind that diarrhea, nausea and vomiting may be caused by something other than food poisoning  –  for example viruses, such as norovirus, IBS (sensitive bowel) or peptic ulcer.

Prevention and Protection

  • Thaw food properly 
  • cook food thoroughly
  • avoid buffets where many come in contact with the food
  • wash your hands before cooking
  • wash knives and cutting boards thoroughly if you have to cut first raw meat and then vegetables.


It is important to replace the fluid that the body loses, but usually no other treatment is required for food poisoning. The problem usually passes within 12-24 hours. In some cases, if symptoms don’t resolve, an investigation may be required. This may lead to antibiotic treatment or if the food poisoning has been caused by parasites, poisons or chemicals, urgent care may be needed.

What you can do for yourself

Vomiting and diarrhea can make the body dehydrated. Therefore, you need to get enough fluid (small amounts of water at frequent intervals is advised). This is especially important if you are pregnant and get food poisoning. When you have stopped vomiting, you can start eating again. Small dishes are advised, and bland foods like broth, soup, rice and white bread are easiest to digest. Don’t eat or drink milk products until the stomach has recovered.


If you are taking birth control pills, bear in mind that severe diarrhea and vomiting can affect your contraceptive protection.

When to consult a doctor

If you or your child have severe diarrhea or vomiting that doesn’t resolve within 24hrs, you should contact a doctor. This also applies to severe abdominal pain, high fever or if you still feel sick, tired and weak after a few days. Serious symptoms of dehydration should also be followed up with a doctor.


If you have blood in the stool or vomit blood, you should get urgent medical help. This also applies to severe abdominal pain that doesn’t pass, high fever and chills.
If you suspect that you have eaten a toxic substance, you should contact an emergency department.

How APPOTEK can help

APPOTEK can help you with food poisoning. During the initial consultation, a nurse or doctor will make an individual assessment based on your symptoms. You may then be prescribed medicine or referred for further treatment. A physical examination is often required if an upset stomach is accompanied by abdominal pain. If your child has a problem, he or she will usually need a physical examination.


Valeria Chernikova, Neurologist, M.D.