Quick answer
What is norovirus?
Norovirus is a highly contagious stomach bug that causes sudden vomiting and diarrhoea. Most people recover within 2 to 3 days with rest and plenty of fluids. Stay off work or school until 48 hours after symptoms stop, and seek help if you cannot keep fluids down or show signs of dehydration.
What is norovirus?
Norovirus — often called the “winter vomiting bug” — is a very contagious virus that causes gastroenteritis (inflammation of the stomach and gut). It is one of the most common stomach bugs in the UK and causes large outbreaks in winter, particularly in hospitals, care homes, schools and cruise ships.
Symptoms
Norovirus usually starts suddenly, within one to two days of infection. Symptoms can include:
- nausea and vomiting — often severe at first
- watery diarrhoea
- stomach cramps
- a mild fever, headache or aching limbs
Most people feel very unwell for one to two days, then improve quickly. Vulnerable people — babies, older adults and those with weakened immune systems — can become dehydrated more easily.
How it spreads
Norovirus spreads easily through:
- close contact with someone who is infected
- touching contaminated surfaces then touching your mouth
- eating food handled by someone with the virus
Only a few virus particles are needed to cause illness. Alcohol hand gels are less effective against norovirus than thorough hand washing with soap and water.
Recovering at home
There is no specific cure, but most people recover with:
- Frequent small sips of fluid — water, diluted squash, or oral rehydration salts from a pharmacy.
- Rest — your body needs energy to fight the infection.
- Plain food when ready — toast, rice, bananas, soup. Avoid fatty or spicy food until fully recovered.
Do not take anti-diarrhoea medicines unless a pharmacist or doctor advises them — they can sometimes prolong illness.
Preventing spread in your household
- Wash hands thoroughly and often, especially after using the toilet and before eating.
- Clean toilet seats, flush handles, taps and door handles with bleach-based products.
- Do not share towels or flannels.
- Avoid preparing food for others until 48 hours after symptoms stop.
- Wash soiled clothing separately on a hot wash.
When to seek help
Contact NHS 111 or a GP if you cannot keep fluids down, show signs of dehydration, or symptoms last longer than expected. Do not visit a GP surgery or hospital in person while you may still be infectious unless you have been told to — call first for advice.
Norovirus vs other tummy bugs
Norovirus is one cause of gastroenteritis. Other viruses and bacteria can cause similar symptoms. If many people become ill after the same meal, food poisoning may be more likely — though norovirus can also spread through contaminated food.
Common questions
- How long does norovirus last?
- Most people feel better within two to three days. Vomiting often settles within 24 to 48 hours, though diarrhoea can last a little longer. You remain infectious for 48 hours after symptoms stop.
- What is the best treatment for norovirus?
- Rest and plenty of fluids are the main treatment. Sip water or oral rehydration solutions frequently. Eat plain foods when you can tolerate them. There is no specific antiviral medicine for norovirus.
- How can I stop norovirus spreading?
- Wash hands thoroughly with soap and water (alcohol gel is less effective against norovirus), clean contaminated surfaces, do not prepare food for others while ill, and stay off work or school for 48 hours after symptoms end.
- Is norovirus the same as food poisoning?
- Norovirus can spread through contaminated food, but it also spreads easily from person to person. Food poisoning has many causes — see our food poisoning guide if you suspect a specific meal.
- When can I return to work after norovirus?
- Stay home for at least 48 hours after your last episode of vomiting or diarrhoea. This reduces the risk of passing the virus to colleagues, patients or classmates.