What should you know about catching stomach flu?

This can happen through close contact with an infected person, contaminated hands, shared surfaces, food, or water. The term can be misleading: stomach flu is not influenza, the respiratory infection. Several viruses can cause gastroenteritis, so having it once does not rule out catching another infection later.

Transmission is especially easy when someone with vomiting or diarrhoea prepares food, shares a bathroom, or touches objects before washing their hands. Tiny droplets released during vomiting can also settle on nearby surfaces. A person may spread the virus before they realise they are ill and for a period after symptoms improve.

Common features include nausea, vomiting, watery diarrhoea, stomach cramps, and sometimes fever or reduced appetite. Symptoms can cause fluid and salt loss; dry mouth, dark urine, dizziness, unusual sleepiness, or passing very little urine can signal dehydration. Read more about [Gastroenteritis](/conditions/gastroenteritis/) and [Dehydration](/conditions/dehydration/).

Wash hands carefully with soap and running water after using the toilet, changing a nappy, cleaning vomit, and before eating or preparing food. Hand sanitiser may not work as well against some stomach viruses. Avoid preparing food for other people while ill, and clean frequently touched bathroom and kitchen surfaces with an appropriate disinfectant.

Do not share towels, utensils, or drinks. Wash soiled clothing and bedding separately when possible, and handle them without shaking. If symptoms begin, take frequent small sips of water or an oral rehydration drink. Eat light foods when you feel able; rest and avoid alcohol. More detail is available about [Diarrhoea](/symptoms/diarrhoea/) and [Nausea](/symptoms/nausea/).

Seek urgent medical help for severe dehydration, fainting, confusion, severe or worsening abdominal pain, blood in vomit or stool, or vomit that prevents you from keeping fluids down. Get prompt advice for a baby, older adult, pregnant person, or anyone with a weakened immune system who develops repeated vomiting or diarrhoea.

Contact a clinician if symptoms are not settling, you have a persistent fever, or you are unsure whether the illness is gastroenteritis. [Fever](/symptoms/fever/) and [Abdominal Pain](/symptoms/abdominal-pain/) may have causes that need a different assessment.

Ask which fluids are most suitable, how to recognise dehydration in your situation, and how long to avoid preparing food or sharing close contact. If a child is affected, ask about feeding, oral rehydration, and whether vaccination or a specific infection such as [Rotavirus Infection](/conditions/rotavirus-infection/) is relevant.