Symptoms of norovirus 

The first sign of norovirus is usually suddenly feeling sick followed by forceful vomiting and watery diarrhoea.

Some people may also have:

  • a raised temperature (over 38°C/100.4°F)
  • headaches 
  • painful stomach cramps
  • aching limbs

Symptoms usually appear one to two days after you become infected, but they can start sooner. Most people make a full recovery within a couple of days.

Apart from the risk of dehydration, norovirus isn't usually dangerous and there are no long-lasting effects from having the illness. However, it can be pretty unpleasant while you have it.


The main risk from norovirus is dehydration from your body losing water and salts from vomiting and diarrhoea.

Thirst is the first sign of dehydration. Other symptoms include:

  • dizziness or lightheadedness
  • headache
  • tiredness
  • dry mouth, lips and eyes
  • dark, concentrated urine
  • only passing small amounts of urine (less than three to four times a day)

Mild dehydration is common and can easily be reversed by making sure you have plenty to drink.

The young and elderly are more at risk of becoming dehydrated. It's therefore very important that you seek medical attention immediately if you think your child or an elderly relative is becoming dehydrated.

Severe dehydration

If you don't replace the lost fluid, dehydration will get worse and could lead to complications, such as low blood pressure and kidney failure. It can even be fatal.

As well as severe thirst, you may also have:

  • dry, wrinkled skin
  • an inability to urinate
  • irritability
  • sunken eyes
  • a weak pulse
  • a rapid heartbeat
  • cold hands and feet
  • seizures

If you or your child has any symptoms of severe dehydration after catching a norovirus infection, seek medical attention as soon as possible.

Read more about treating norovirus.

Diagnosing norovirus

The only way of diagnosing norovirus is to test a stool sample in a laboratory.

However, this isn't usually necessary because treatment is the same for all causes of stomach bugs.

If you have a sudden episode of vomiting and diarrhoea, it's likely you have norovirus.

Can I get norovirus again?

Yes, you can get norovirus more than once. The virus is always changing, which means your body is unable to build up resistance to it.

Page last reviewed: 20/01/2014

Next review due: 20/01/2016