How Long Does Norovirus Last? Incubation Period and Timeline

Norovirus usually lasts 1 to 3 days. Symptoms start suddenly, 12 to 48 hours after you swallow the virus, hit hardest in the first 24 hours, and then fade over the next day or two, according to the Centers for Disease Control and Prevention (CDC). The illness is short, but two other clocks run longer: you should stay home for 48 hours after the last symptom, and the virus can stay in your stool for two weeks or more after you feel fine.

This page walks through the whole timeline, from exposure to the day you can safely cook for other people again. It is part of our norovirus symptoms guide.

Norovirus timeline at a glance

Stage	When	What is happening	Can you spread it?
Exposure	Hour 0	Virus is swallowed from hands, food, water, or a contaminated surface	No
Incubation	12 to 48 hours (median about 29 hours)	No symptoms; the virus multiplies in the small intestine	Possibly, in the last hours before symptoms
Acute illness	1 to 3 days	Sudden vomiting, watery diarrhea, nausea, stomach cramps; sometimes low fever, headache, body aches	Yes, this is the peak
Early recovery	First 48 hours after symptoms stop	Tired, weak appetite, stools still loose	Yes, still very likely
Late shedding	2 weeks or more after you feel better	You feel normal; virus is still in stool	Yes, at a lower level; handwashing matters most here

Times are from the CDC and from published studies cited in the sources below. Individual cases vary.

Norovirus incubation period: how soon after exposure do you get sick?

The norovirus incubation period is 12 to 48 hours. That is the CDC's range, and it matches what researchers found when they pooled data from many outbreaks: a systematic review in BMC Infectious Diseases put the median incubation at 1.2 days, or roughly 29 hours. In that analysis about 5 percent of people were sick within half a day, and 95 percent of those who were going to get sick had symptoms by 2.6 days.

In practical terms:

• Under 6 hours after a meal: norovirus is unlikely. Vomiting that fast points to a bacterial toxin such as Staphylococcus aureus. See norovirus vs. food poisoning.
• 12 to 48 hours: the classic norovirus window.
• After 3 full days with no symptoms: you have very likely escaped that particular exposure.

A worked example

Your child starts vomiting at 9 p.m. on Friday. You cleaned up and shared a bathroom all weekend. Counting from Friday night:

• The earliest you would expect symptoms is Saturday morning.
• The most likely window is Saturday evening through Sunday night.
• If you are still well on Monday evening, that first exposure probably did not infect you.

The catch is that exposure in a household is not a single moment. A sick child keeps shedding virus, so the clock restarts with each contact. That is why families often see a second person fall ill two to four days after the first, and a third a couple of days after that. Good handwashing and bleach-based cleaning can break that chain; the steps are in how to kill norovirus on surfaces and laundry.

How long do norovirus symptoms last?

Most people with norovirus get better within 1 to 3 days, the CDC says. Outbreak investigators use an even tighter rule of thumb, known as the Kaplan criteria: in a typical norovirus outbreak, the average illness lasts 12 to 60 hours.

Hours 0 to 24: the worst of it

Norovirus rarely builds slowly. Many people go from feeling fine to vomiting within an hour or two. Vomiting tends to dominate the first 12 to 24 hours, especially in children. Watery diarrhea may start at the same time or a few hours later. Cramps come in waves. A low fever, chills, headache, and aching muscles are common enough that people mistake the first night for influenza.

The job in this phase is simple: small, frequent sips of fluid. Details are in norovirus treatment at home.

Hours 24 to 48: turning the corner

Vomiting usually eases first, often within a day. Diarrhea commonly continues into the second day. Nausea comes and goes, and the idea of food is unappealing. Most adults can keep fluids down by now and can start eating small amounts of plain food.

Hours 48 to 72: winding down

By the third day, most healthy adults and older children have fewer and firmer stools and are mainly tired. If vomiting is still frequent on day three, or diarrhea is not clearly improving, that is a reason to call a doctor rather than wait.

How long does norovirus diarrhea last?

Usually one to three days. Stools can stay softer than normal for several more days while the lining of the intestine recovers. Some people have trouble digesting milk and other lactose-containing foods for a while after a bout of viral gastroenteritis; the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) says this can last a month or more. Loose stools after dairy in the weeks after norovirus are more likely to be that than a relapse.

When norovirus lasts longer than 3 days

Three days is typical, not a guarantee. CDC outbreak guidance notes that longer illness of 4 to 6 days can occur, particularly in young children, older adults, and people who are hospitalized. The groups in which norovirus tends to run longer or harder:

Group	What to expect	Main risk
Healthy adults and teens	1 to 3 days	Mild dehydration
Babies and young children	Often 1 to 3 days, sometimes 4 to 6	Dehydration develops fast; see norovirus in babies and kids
Adults 65 and older	Sometimes 4 to 6 days; weakness can linger	Dehydration, falls, kidney strain, worsening of chronic conditions
People with weakened immune systems	Can last weeks to months	Chronic diarrhea and weight loss; needs medical care
Pregnant women	Usually 1 to 3 days	Dehydration; see norovirus during pregnancy

Can norovirus last a week? In an otherwise healthy adult that is unusual. A week of diarrhea deserves a call to your doctor, because other causes become more likely: bacteria such as Salmonella or Campylobacter, parasites such as Giardia, a C. difficile infection after antibiotics, or a different virus. In people who have had an organ transplant, are on chemotherapy, or have another serious immune problem, norovirus itself can become a long-running infection, and doctors manage it differently.

How long does norovirus last in your home?

The illness is over in days, but the virus left behind is tougher than the person who had it. The CDC says norovirus can persist on surfaces for days or weeks and is resistant to many common disinfectants. That is the reason a family can pass it around for two weeks even though each person is sick for only a day or two, and the reason a quick wipe with an ordinary cleaning spray is not enough after someone vomits.

Two habits shorten the household outbreak more than anything else: disinfecting the bathroom and high-touch surfaces with a bleach solution on the day symptoms start and again when they end, and washing hands with soap and water rather than relying on hand sanitizer, which does not work well against this virus.

How long does a stomach bug last if it is not norovirus?

"Stomach bug" and "stomach flu" are everyday names for viral gastroenteritis. Norovirus is the most common cause in the United States, but it is not the only one, and the others last longer. The NIDDK gives these typical times:

Virus	Symptoms start after	Symptoms last	Who gets it most
Norovirus	12 to 48 hours	1 to 3 days	All ages
Rotavirus	About 2 days	3 to 8 days	Infants and young children, especially if unvaccinated
Adenovirus (enteric types)	3 to 10 days	1 to 2 weeks	Young children
Astrovirus	4 to 5 days	1 to 4 days	Young children, older adults

So if a "24-hour bug" came on fast and was over in a day or two, norovirus is the likeliest culprit. A toddler with a week of watery diarrhea is more likely to have rotavirus or adenovirus.

How long until you feel normal again?

The vomiting and diarrhea end quickly; the washed-out feeling takes longer. It is common to feel weak and tired for a few days after the last symptom, mostly from fluid loss, lost sleep, and a couple of days of barely eating. A reasonable recovery plan:

1. Day 1 after symptoms stop: keep drinking, eat small regular meals, rest. Stay home.
2. Day 2: normal food if you want it. Still stay home from work, school, or daycare, and do not cook for others.
3. Day 3 onward: back to your routine. Ease into hard exercise, since you may still be slightly dehydrated.
4. For the next two weeks: wash hands with soap and water after every bathroom visit and before handling food.

If your appetite and energy are not back within about a week, or you are losing weight, check in with a health care provider.

How long are you contagious?

Longer than you are sick. You are most contagious while you have symptoms, especially vomiting, and for the first few days after you feel better. The CDC asks people to stay home, and not to prepare food or care for others, for at least 48 hours after symptoms stop. Virus can still be found in stool for two weeks or more; in one study in which volunteers were deliberately infected, shedding lasted a median of 28 days. The full breakdown, including when kids can return to daycare, is in how long norovirus is contagious.

When the clock says to call a doctor

Duration is one of the most useful warning signs. Call a doctor or use urgent care if any of these apply, based on NIDDK and CDC guidance:

• An adult has diarrhea for more than 2 days, or cannot keep liquids down for 24 hours.
• A child has diarrhea for more than 1 day, or an infant has any fever.
• Vomiting is so frequent that no fluids stay down.
• There is blood or pus in the stool, or stools are black and tarry. Norovirus does not normally cause bloody diarrhea.
• Fever is above 102°F in an adult or older child.
• Pain in the abdomen is severe or constant rather than crampy and coming in waves.
• There are signs of dehydration: very little urine, dark urine, dry mouth, dizziness on standing; in a baby, no wet diaper for 3 hours or more, no tears, or a sunken soft spot.

Call 911 for confusion, fainting, a seizure, trouble breathing, a person who cannot be woken or is too weak to stand, or a child who is limp and unresponsive.

Back-to-normal checklist

• No vomiting or diarrhea for 48 hours before returning to work, school, or daycare.
• If you work with food, in health care, or in child care, tell your employer; many workplaces and local health codes have their own return rules.
• Bathroom, door handles, faucet handles, and phone disinfected with a bleach solution or a product on EPA's List G.
• Bedding, towels, and soiled clothes washed hot on the longest cycle and dried on high heat.
• No swimming pools until diarrhea has fully stopped; the CDC's general advice for diarrheal illness is to stay out of the water while you have diarrhea.
• Soap-and-water handwashing kept up for at least two weeks.

Can you get norovirus again right after recovering?

You can get norovirus many times in your life. There are many different types, and infection with one does not reliably protect against the others, the CDC notes. Protection against the same type does develop, but nobody knows exactly how long it lasts; older volunteer studies suggested as little as a few months. Catching a second, different strain within the same winter is possible, though it is not the usual experience. If symptoms return within a few days of improving, it is more often a household reinfection cycle, a food that did not sit well, or a different illness, and it is worth a call to your doctor if it happens.