Food Poisoning

Medically reviewed by:

Dr Dan Bunstone - Medical Officer

Updated: Aug 18, 2021

Next review: Aug 18, 2022

Food poisoning is caused by eating food or drinking something that is contaminated with either bacteria, a virus or parasite. It is not usually serious, and most people will get over it within a few days to a week by resting and recuperating at home.

However, sometimes you may need medical attention, for example, if it is particularly severe, is persistent or if you fall into an ‘at risk’ group, which includes those under 5, over 60, if you are pregnant, or have a long-term condition or illness that weakens your immune system.

Food poisoning symptoms usually occur within a few hours to a few days of eating or drinking the infected item. However, it is possible for symptoms to show themselves even after several weeks.

The symptoms can vary depending on the cause of the infection, but the most common are diarrhoea and vomiting.

You may also have:

Nausea
Stomach pain or cramps
Loss of appetite
Weakness and a lack of energy
Muscle aches
A fever or high temperature
Chills
A headache

In rarer instances, you may also experience the following symptoms. If you do, you should contact a doctor straight away:

Diarrhoea that is persistent for three days or more
A high fever of 38.5 Celsius or more
Blood in your urine
Blood in your vomit
Difficulty speaking or seeing
Muscle weakness, including tingling in the arms
Severe dehydration symptoms, such as a dry mouth, excessive thirst, dizziness, feelings of being lightheaded, little urination or severe weakness

For a full list of food poisoning symptoms, click here.

Food poisoning is caused by eating food that is contaminated with bacteria, a virus or a parasite. The most common of these are:

Campylobacter
Escherichia coli (E. coli)
Salmonella
Listeria
Shigella
Norovirus
Rotavirus

Read more about the different causes of food poisoning.

Our doctor will ask you about the symptoms that you are experiencing, how long you’ve had them and what you think caused it.

The doctors is also likely to try and find out what have eaten or drunk recently, and whether or not you have you have just returned from a trip abroad. This will help them confirm what is causing your food poisoning and whether you need treatment.

In severe cases of food poisoning, or when a diagnosis is unclear, the doctor may refer you for further tests. These might include a blood tests or a stool sample to find out if the food poisoning has been caused by bacteria, which may need anti-biotic treatment, or to rule out other health conditions.

ails on what will happen during your online consultation, please click here.

Most cases of food poisoning during pregnancy are harmless to you and your baby, but there is one strain that is caused by listeria bacteria, which can be very harmful. In early pregnancy it could lead to a miscarriage, while later on it may cause a stillbirth, premature birth or fatal infection.

If you are pregnant and experience flu-like symptoms, vomiting, nausea, diarrhoea, muscle aches or fever, then you should contact a doctor for a diagnosis and treatment straight away.

Like we said, most cases will not be a cause for concern, but if you are at all concerned about having food poisoning while pregnant and want to know more about how it may affect your pregnancy, our doctors are here to help. They will provide the support, advice and treatment (if required) that you need.

Read further information about which foods you should avoid to limit the risk of food poisoning and how food poisoning affects pregnancy.

Most cases of food poisoning are not serious and can be managed at home.

However, it is a good idea to get advice from a medical professional if:

It is a severe case of food poisoning
It is persistent
You are elderly
If you are pregnant
It is someone very young suffering,
You are vulnerable to infection because of a weakened immune system
You have an underlying health condition

A doctor will be able to assess your symptoms and their severity to determine if treatment is required. Treatment for food poisoning includes:

Oral rehydration solutions
Anti-emetics to stop vomiting
Antibiotics (if it is a bacterial infection)

It is important to drink fluids, even if you can only manage little sips, as the condition can cause dehydration. Find out more about how to treat food poisoning.

Dr Dan Bunstone - Medical Officer

What is food poisoning?

Food poisoning symptoms

Food poisoning causes

Food poisoning diagnosis

Food poisoning in pregnancy

Food poisoning treatment

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