The most common symptoms of norovirus are:
Norovirus causes inflammation of the stomach or intestines. This is called acute gastroenteritis.
A person usually develops symptoms 12 to 48 hours after being exposed to norovirus. Most people with norovirus illness get better within 1 to 3 days.
If you have norovirus illness, you can feel extremely ill, and vomit or have diarrhea many times a day. This can lead to dehydration, especially in young children, older adults, and people with other illnesses.
Symptoms of dehydration include:
feeling dizzy when standing up
Children who are dehydrated may cry with few or no tears and be unusually sleepy or fussy.
Do you think you have the stomach flu or a stomach bug?
It’s probably norovirus, a common virus that is not related to the flu. Norovirus is the most common cause of vomiting and diarrhea, and foodborne illness.