Norovirus: Symptoms, Prevention, and What to Do If You Catch the Stomach Flu Bug
Handwashing and disinfection can keep families safe from sudden stomach infections.
What Is Norovirus—and Why Is It Called the Stomach Flu?
Norovirus is a highly contagious virus that causes an intense and often sudden onset of gastrointestinal illness. Commonly known as the “stomach flu” or “stomach bug,” norovirus is not related to the influenza virus; rather, it leads to acute gastroenteritis—inflammation of the stomach and intestines—which causes symptoms like nausea, vomiting, diarrhea, and stomach pain.
Unlike the “flu,” which is caused by the influenza virus and primarily affects the respiratory system, norovirus targets the gastrointestinal tract. Despite being a year-round threat, norovirus is best known for causing wintertime outbreaks, typically from November through April.
How Does Norovirus Spread?
- Contaminated food or water: Eating raw or undercooked shellfish, or consuming food and beverages handled by someone infected with norovirus.
- Direct contact: Touching someone who is infected or handling items they have touched (such as doorknobs and shared surfaces) and then touching your mouth.
- Aerosolized particles: In rare cases, microscopic droplets from vomit can spread virus particles through the air.
Norovirus is extremely infectious; it only takes a few virus particles to cause illness, and people are contagious from the moment they start feeling sick, and even for a few days after symptoms resolve.
Who Gets Norovirus? Is Anyone More at Risk?
Anyone can catch norovirus, regardless of age or prior exposure, because there are many types and infection with one does not guarantee immunity to others. Certain groups, however, face greater risk of severe illness or complications:
- Young children: Higher chance of becoming dehydrated quickly.
- Older adults: Prone to more severe symptoms and longer recovery.
- People with weakened immune systems: May experience prolonged or more intense illness.
Almost everyone will contract norovirus at least once in their lifetime, and it is the leading cause of foodborne illness in the United States.
What Are the Symptoms of Norovirus?
Norovirus has a reputation for striking with remarkable speed. Symptoms often appear 12 to 48 hours after exposure and tend to be highly unpleasant but typically short-lived. The most common norovirus symptoms include:
- Nausea and sudden vomiting
- Watery diarrhea
- Stomach pain or cramping
- Low-grade fever
- Chills
- Headache
- Muscle aches and fatigue
What others are reading
Some people experience additional symptoms such as loss of appetite, body aches, and a general sense of tiredness.
Norovirus Symptom Timeline
| Time After Exposure | Symptoms |
|---|---|
| 12-48 hours | Rapid onset of nausea, vomiting, diarrhea, cramps |
| 24-48 hours | Symptoms peak in severity |
| 1-3 days | Recovery period; symptoms subside for most |
Signs of Dehydration
- Decreased urination
- Dry mouth or throat
- Extreme thirst
- Dizziness or lightheadedness
- Crying with few or no tears (in children)
- Unusual sleepiness or fussiness (in children)
If you or your child show these signs, seek medical care immediately.
How Serious Is Norovirus? When Should You See a Doctor?
For most healthy people, norovirus causes 1 to 3 days of misery but is rarely life-threatening. The biggest risk is dehydration, particularly among:
- Young children
- Older adults
- People with immune system problems or other health issues
Seek immediate medical help if you or someone you care for experiences:
- Symptoms of severe dehydration (listed above)
- Unable to keep fluids down
- Vomiting or diarrhea lasting longer than 72 hours
- Dark urine, very dry mouth, or extreme drowsiness
- Blood in vomit or stool
For most people, the illness resolves without medication. However, in rare cases—especially in those at high risk—complications can be severe.
How Can You Prevent Norovirus?
There are no vaccines to prevent norovirus infection, but simple hygiene practices are highly effective:
- Wash your hands often with soap and warm water, especially after using the restroom, changing diapers, and before eating or handling food. Hand sanitizers are less effective with norovirus.
- Disinfect surfaces using a chlorine bleach solution, particularly after someone has been sick.
- Wash produce and cook seafood thoroughly. Raw oysters and shellfish are common sources.
- Stay home when you are sick and for at least two days after symptoms resolve to prevent spreading the virus to others.
- Handle and dispose of vomit and feces carefully, using gloves if possible and thoroughly washing hands afterward.
Quick Tip: Launder soiled clothes and linens promptly using hot water and detergent, and machine dry if possible.
What Should You Do If You Catch Norovirus?
There is no specific antiviral treatment for norovirus. Most people recover at home by following these care tips:
- Drink plenty of fluids to replace those lost from vomiting and diarrhea. This helps prevent dehydration. Try clear broth, oral rehydration solutions, or water. Avoid sugary, caffeinated, or alcoholic beverages as they may worsen symptoms.
- Rest as much as possible—your body needs time to recover.
- Gradually reintroduce food once vomiting has stopped, starting with bland items such as toast, crackers, rice, bananas, or applesauce.
- Monitor for worsening symptoms or signs of dehydration (see above).
Do not take anti-diarrheal medications unless advised by your healthcare provider, as they may prolong the illness in some cases.
How Long Is Norovirus Contagious?
People with norovirus are most contagious while experiencing symptoms and for at least several days after recovery. In some cases, the virus can be shed in stool for up to two weeks, even after you start feeling better. For this reason, experts recommend staying home from work, school, or childcare and avoiding food preparation duties for at least 48 hours after symptoms resolve.
Norovirus vs. Food Poisoning and the Flu: How Can You Tell the Difference?
| Illness | Key Symptoms | Primary System Affected | Onset/Duration | Transmission |
|---|---|---|---|---|
| Norovirus | Nausea, vomiting, diarrhea, stomach cramps | Digestive tract | 12–48 hrs / 1–3 days | Highly contagious; person-to-person, food, surfaces |
| Food Poisoning (Other causes) | Varies (nausea, vomiting, diarrhea, sometimes fever) | Digestive tract | Hours to days / 1–7 days (depending on organism) | Contaminated food/water; not usually person-to-person |
| Influenza (Flu) | Fever, chills, headache, muscle aches, cough, sore throat | Respiratory system | 1–4 days / up to 2 weeks | Airborne droplets, close contact |
Norovirus is often confused with general “food poisoning” or the seasonal flu. The biggest clues are the sudden gastrointestinal onset and rapid spread from person to person. Whereas influenza typically includes respiratory symptoms and a longer duration, norovirus is characterized by abrupt and severe stomach upset.
Frequently Asked Questions (FAQs)
How long does norovirus last?
Symptoms typically last 1 to 3 days for most healthy people, but it may be longer in young children, older adults, and individuals with weakened immune systems.
How can I avoid catching norovirus?
Practice thorough handwashing, disinfect contaminated surfaces, avoid sharing food or utensils with sick people, and wash produce and seafood completely before eating.
Is there a vaccine for norovirus?
Currently, there is no vaccine for norovirus. Prevention focuses on strict hygiene and sanitation.
Can you get norovirus more than once?
Yes, immunity is limited and short-lasting; you can get sick with different strains of norovirus multiple times in your life.
What should I eat when recovering?
After vomiting stops, eat easy-to-digest foods such as toast, rice, bananas, and applesauce. Avoid dairy, fatty foods, caffeine, and alcohol until fully recovered.
Should I take medicine for norovirus?
Medications are not usually recommended for norovirus. Only take what a healthcare provider prescribes, and focus on hydration and rest.
Is norovirus ever dangerous?
While most will recover fully at home, norovirus can be dangerous if it leads to severe dehydration, especially in vulnerable populations. Seek prompt medical care for persistent symptoms or any concerns.
Source: AFC Urgent Care
Source: Good Housekeeping Health
Source: Safe Medication
Source: CDC Norovirus
References
- https://www.afcurgentcare.com/knoxville-tn/blog/what-are-the-first-signs-of-norovirus/
- https://www.goodhousekeeping.com/health/a63396308/norovirus-symptoms-causes-treatments/
- https://www.safemedication.com/pharmacist-insights/2024/03/11/norovirus-what-to-know
- https://www.cdc.gov/norovirus/about/index.html
- https://dph.illinois.gov/topics-services/diseases-and-conditions/diseases-a-z-list/diseases/noroviruses.html
- https://www.cdph.ca.gov/Programs/CID/DCDC/Pages/Norovirus.aspx
- https://my.clevelandclinic.org/health/diseases/17703-norovirus
- https://indianriver.floridahealth.gov/newsroom/2023/04/Norovirus.html
- https://www.nfid.org/dont-let-norovirus-ruin-summer-plans/
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