Food Poisoning vs Norovirus

By the AllHealth UK editorial teamLast reviewed 26 August 2026Next review due 26 February 2027Compiled from published NHS and NICE guidance. Not reviewed by a clinician.

Is it food poisoning or norovirus?

You often cannot tell, and the home treatment is identical. Food poisoning usually starts within hours or days of a particular meal and tends to affect only the people who ate it. Norovirus starts suddenly, spreads person to person, and typically runs through a household, school or care home. Both need fluids and rest, and both keep you off work for 48 hours.

Immediate action required: call 999 or go to A&E if

You are vomiting blood, or vomit that looks like ground coffee
Green vomit in an adult, or yellow-green vomit in a child
A sudden, severe tummy ache, or a sudden, severe headache
A stiff neck and pain when looking at bright lights
Blue, grey, pale or blotchy skin, lips or tongue, or confusion

If you are weighing up whether it is bad enough to call, that is itself a reason to call. Nobody is annoyed by a 999 call that turns out to be the less serious of the two.

Food Poisoning compared with Norovirus
Feature	Food Poisoning	Norovirus
Typical signs	Starts hours to days after a particular meal — sometimes not for a few weeks Only the people who ate that food are ill Diarrhoea often the leading symptom Tummy pain and a high temperature	Sudden onset, usually vomiting first Caught from someone who was recently ill Outbreaks in schools, wards and care homes Headache and aching arms and legs Hand gel does not kill it — soap and water does
How long it lasts	Usually better within a week	Usually better in 2 to 3 days
What helps	Fluids and rest; rehydration sachets from a pharmacist. Stay off work or school until 48 hours after the last episode. Call 111 now if you have bloody diarrhoea or bleeding from your bottom, cannot keep any fluid down, have diarrhoea for more than 7 days or vomiting for more than 2 days, or are worried about a baby under 12 months.	Fluids and rest; wash hands with soap and water, not alcohol gel. Stay off work or school until 48 hours after the last episode. Call 111 now if you have bloody diarrhoea or bleeding from your bottom, cannot keep any fluid down, have diarrhoea for more than 7 days or vomiting for more than 2 days, or are worried about a baby under 12 months.
What to do	Self-care at home	Self-care at home

Sources and further reading

This page was written from the following published guidance. All links checked 26 August 2026.

What to do next

Not sure whether this needs a doctor? These are your options, cheapest and fastest first.