What is norovirus? What are the symptoms and how to avoid getting sick this winter

Ah, the classic signs of winter: Freezing temperatures, icy roads and empty tissue boxes.

It's no secret that winter is a time when illness is prominent. Coughs, colds, and viruses are seemingly running rampant this time of year. This is thanks to the drier air and an influx of time spent indoors, according to the Mayo Clinic.

This year, in addition to the typically annual illnesses, there is a rising number of norovirus outbreaks, otherwise known as a "stomach bug," according to the U.S. Center for Disease Control and Prevention. In December, the CDC reported 91 cases of norovirus, more than double the highest number recorded between 2021 and 2024.

Amid the stomach bug spike, here's what you need to know about norovirus and how to avoid getting sick this season.

What is norovirus?

Norovirus is an extremely contagious illness that commonly causes vomiting and diarrhea, according to the CDC. Norovirus causes acute gastroenteritis, an inflammation of the stomach or intestines.

You can get norovirus by accidentally getting tiny particles of feces or vomit in your mouth from another infected person. Norovirus is commonly spread through contaminated food and/or water.

It's important to note that norovirus and the flu are two different illnesses; they are unrelated.

What are the symptoms of norovirus?

The following are symptoms of norovirus infection, according to the Minnesota Department of Health and the Cleveland Clinic:

• Vomiting

• Diarrhea

• Stomach cramping

• Urinating less or having dark-colored pee

• Dry mouth

• Feeling weak

• Dizziness

Less common symptoms are:

• Low-grade fever or chills

• Headache

• Muscle aches

Does Lysol kill norovirus?

Though hand sanitizer does not kill norovirus, disinfectants, including Lysol products, should kill the virus, according to the University of Colorado Health.

Can you get norovirus twice?

Yes, you can get norovirus multiple times because there are many different strands of noroviruses, according to the CDC. Infection with one type of norovirus may not protect you against other types.

How long does norovirus last?

Most people with norovirus illness recover in one to three days, according to the CDC.

Symptoms of norovirus are likely to appear 12-48 hours after exposure. The CDC recommends staying home for two days after you feel the symptoms subside.

Is norovirus seasonal?

Yes, norovirus is seasonal and very common. January is in the middle of norovirus season, which generally runs from November to April, according to Cleveland Clinic.

How to avoid getting norovirus

Here are some tips to prevent norovirus according to the CDC.

• Wash your hands often with soap and water for at least 20 seconds. Hand sanitizer will not stop the spread of norovirus.

• Carefully wash fruits and vegetables well.

• Cook oysters and other shellfish thoroughly to an internal temperature of at least 145°F.

• Keep raw oysters away from ready-to-eat food in the grocery cart, refrigerator, and on cutting boards.

• After someone vomits or has diarrhea, clean well and disinfect the entire area immediately.

• Immediately remove and wash clothes or linens that may have vomit or poop on them.

This article originally appeared on Knoxville News Sentinel: what is norovirus? What are the norovirus symptoms 2025? What to know