Norovirus, often called the winter vomiting bug or stomach flu, is the most common cause of sudden vomiting and diarrhea worldwide. It is not related to influenza at all. It is miserable, intensely contagious, and tends to sweep through schools, cruise ships, care homes, and households in the colder months. The good news: most healthy people recover fully in a couple of days. This guide explains what to expect and how to look after yourself and your family.
What norovirus feels like
Symptoms usually appear 12 to 48 hours after exposure and come on abruptly. The classic combination is forceful vomiting and watery diarrhea, often with stomach cramps, nausea, a low-grade fever, and aching muscles. Because it arrives so suddenly, many people can pinpoint almost the hour they fell ill.
How long it lasts
The acute illness is typically short, lasting one to three days. However, you can still spread the virus for at least 48 hours after symptoms stop, and it survives on surfaces for days. That is why outbreaks are so hard to contain.
Hand sanitizer is not enough
Alcohol gels do not reliably kill norovirus. Wash hands with soap and warm water for 20 seconds, especially after using the toilet and before handling food. Clean contaminated surfaces with a bleach-based product.
The single most important thing: stay hydrated
The real danger of norovirus is dehydration from fluid loss, particularly in young children, older adults, and people with chronic illness. Replacing fluids and salts matters more than stopping the diarrhea.
- Sip small amounts of fluid frequently rather than gulping large volumes, which can trigger more vomiting.
- Use an oral rehydration solution from a pharmacy for the best balance of water, salts, and sugar.
- Ease back to bland, plain foods such as toast, rice, bananas, or crackers once vomiting settles.
- Avoid alcohol, very sugary drinks, and caffeine while recovering.
About anti-diarrheal and anti-nausea medicines
Over-the-counter remedies are sometimes used in adults, but they are not right for everyone and are generally not recommended for children. Speak to a pharmacist or doctor before using them, especially if you have a fever, blood in your stool, or a long-term condition. Never give anti-diarrheal medicine to a child without professional advice.
Get urgent help if you see signs of severe dehydration
Very little or no urine, dizziness or fainting on standing, sunken eyes, no tears, lethargy or confusion, blood in vomit or stool, severe or constant abdominal pain, or a high fever that won't come down. In infants, watch for a sunken soft spot, no wet diapers for many hours, and unusual drowsiness. Call 911 (US/CA), 999 (UK), or 112 (EU) if someone is too unwell to drink or cannot be roused.
Stopping it spreading at home
- Keep the ill person away from food preparation and, where possible, use a separate bathroom.
- Wash soiled laundry separately on a hot cycle.
- Do not return to work, school, or social settings until 48 hours after symptoms fully stop.
- Disinfect high-touch surfaces daily during and after the illness.
When to see a clinician
Contact a doctor if symptoms last more than three days, if you cannot keep any fluids down, if you have a weakened immune system, or if you are worried about a child or older relative. A verified doctor on iHealix can assess your dehydration risk, advise on rehydration, and decide whether you need in-person care. This article is for general information and does not replace personalized medical advice.