Table of ContentsView AllTable of ContentsSymptomsTimingCausesDiagnosisTreatmentPreventionWhen to See a Provider
Table of ContentsView All
View All
Table of Contents
Symptoms
Timing
Causes
Diagnosis
Treatment
Prevention
When to See a Provider
It can be hard to tell the difference betweennorovirus(the most common cause of stomach flu) and food poisoning because both cause nausea, vomiting, and stomach pain.
A few signs can differentiate the two, including when symptoms start and how long they last. With food poisoning, symptoms often start sooner than with the stomach bug, sometimes within minutes of eating contaminated food. Norovirus symptoms can take anywhere from 12 to 48 hours to develop.
Verywell / Joules Garcia
Symptoms of Food Poisoning vs. Norovirus
Some of thesymptoms of food poisoningare the same assymptoms of norovirus, so it can be difficult to tell the difference based on symptoms alone.
Food PoisoningNauseaVomitingStomach painCrampingWeaknessDiarrhea (may be watery, bloody, or mucus-like)FeverNorovirusNauseaVomitingStomach painCrampingWeaknessDiarrhea (typically watery)FeverChillsHeadacheMuscle aches
Food PoisoningNauseaVomitingStomach painCrampingWeaknessDiarrhea (may be watery, bloody, or mucus-like)Fever
Nausea
Vomiting
Stomach pain
Cramping
Weakness
Diarrhea (may be watery, bloody, or mucus-like)
Fever
NorovirusNauseaVomitingStomach painCrampingWeaknessDiarrhea (typically watery)FeverChillsHeadacheMuscle aches
Diarrhea (typically watery)
Chills
Headache
Muscle aches
In a nutshell, food poisoning and norovirus both cause severe gastrointestinal symptoms, but norovirus (like most communicable viral diseases) typically leads to flu-like symptoms.
On the other hand, food poisoning is more likely to cause severe gastrointestinal symptoms such as projectile vomiting and bloody stools.Food poisoning and norovirus can cause gastroenteritis — irritation and inflammation of the stomach and intestines.
How Long Do Symptoms Last?Most people recover from food poisoning in 12 to 24 hours.However, people with the stomach flu or norovirus may take longer, with symptoms sometimes persisting for more than a week.
How Long Do Symptoms Last?
Most people recover from food poisoning in 12 to 24 hours.However, people with the stomach flu or norovirus may take longer, with symptoms sometimes persisting for more than a week.
Onset of Food Poisoning vs. Norovirus
How Soon Do Symptoms Start?Signs and symptoms of food poisoning usually begin30 minutes to eight hoursafter eating contaminated food.However, some pathogens may take longer for symptoms to develop. Signs of stomach flu (norovirus) typically start12 to 48 hoursafter exposure to the virus.
How Soon Do Symptoms Start?
Signs and symptoms of food poisoning usually begin30 minutes to eight hoursafter eating contaminated food.However, some pathogens may take longer for symptoms to develop. Signs of stomach flu (norovirus) typically start12 to 48 hoursafter exposure to the virus.
Causes of Food Poisoning vs. Norovirus
Not only are the organisms that cause food poisoning and stomach flu different but so are some of the ways they are spread.
Causes of Food Poisoning
The contamination can occur at several points, including:
Causes of Norovirus or Stomach Bug
Norovirus is the predominant cause of stomach flu in adults, whilerotavirusis the most common cause in children. Other viruses, bacteria, or parasites can also cause other cases of stomach flu.
With Norovirus, the transmission route is broader because the virus tends to be more challenging to neutralize on surfaces than foodborne bacteria.
Norovirus is commonly spread through:
Depending on the conditions, norovirus can live on surfaces for days to several weeks. It is also incredibly challenging to disinfect.Additionally, individuals who have had Norovirus can remain infectious for up to two weeks after their symptoms have resolved.
This is why it is essential to properly disinfect surfaces during and after suspected Norovirus exposure and practice diligent hand hygiene.
How Common Are They?In the United States, an estimated 48 million people get food poisoning, and up to 21 million get norovirus each year.Combined, they are responsible for tens of thousands of emergency room visits and hospitalizations annually.
How Common Are They?
In the United States, an estimated 48 million people get food poisoning, and up to 21 million get norovirus each year.Combined, they are responsible for tens of thousands of emergency room visits and hospitalizations annually.
Diagnosis of Food Poisoning vs. Norovirus
The diagnosis of food poisoning and norovirus is more or less the same, and many of the tools used for the diagnosis (such as stool cultures) check for both bacterial and viral causes.
If you are suspected of having food poisoning or norovirus, the diagnosis will typically involve:
Testing is especially relevant if there is a community outbreak (such as an outbreak on a cruise ship or in a hospital). At other times, testing can help trace the source of food contamination.
On an individual level, the differentiation won’t inherently alter how either disease is treated.
With that said, the differentiation may be essential for those who are at high risk of complications, Including:
Treatment of Food Poisoning vs. Norovirus
The treatment of food poisoning and the stomach flu are similar. Generally speaking,antibiotics(used for bacterial infections) andantivirals(used for viral infections) are of little help once symptoms start. In some cases, they can make things worse.
For most people, treatment can be delivered at home and may include:
Prevention of Food Poisoning vs. Stomach Bug
Food poisoning generally isn’t contagious from person to person in the way that the stomach flu is. Because the modes of transmission are different, there are different precautions you may need to take to avoid getting or spreading these diseases.
Preventing Food Poisoning
To prevent food poisoning, you should as a general rule:
Preventing the Stomach Flu
To prevent the spread of norovirus while someone in your home is sick:
Stay at HomeIf you have symptoms of food poisoning or norovirus, stay home and away from others until your symptoms have completely cleared.
Stay at Home
If you have symptoms of food poisoning or norovirus, stay home and away from others until your symptoms have completely cleared.
When to See Your Healthcare Provider
There are times when you need more than home-based care if you have food poisoning or stomach flu. It’s important to know the signs to prevent potentially serious complications likesevere dehydration.
If you have food poisoning, seek immediate medical care if you have:
If you have norovirus, seek immediate medical care if you have:
Watch for DehydrationDehydration is common if vomiting or diarrhea persists for more than 24 hours and can quickly turn deadly if left untreated.Symptoms of dehydration include:Dark or infrequent urineDry mouthDizzinessWeaknessConfusionFaintingRapid heart rate
Watch for Dehydration
Dehydration is common if vomiting or diarrhea persists for more than 24 hours and can quickly turn deadly if left untreated.Symptoms of dehydration include:Dark or infrequent urineDry mouthDizzinessWeaknessConfusionFaintingRapid heart rate
Dehydration is common if vomiting or diarrhea persists for more than 24 hours and can quickly turn deadly if left untreated.
Symptoms of dehydration include:
Summary
If you develop either condition, watch for signs of dehydration. See a healthcare provider if you have a weak immune system, are pregnant or elderly, or you have severe or lingering symptoms.
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14 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.National Institute of Diabetes and Digestive and Kidney Diseases.Symptoms & causes of food poisoning.National Institute of Diabetes and Digestive and Kidney Diseases.Diagnosis of viral gastroenteritis (“stomach flu”).Centers for Disease Control and Prevention.About Norovirus.Centers for Disease Control and Prevention.Key facts about food poisoning.Centers for Disease Control and Prevention.About food safety.Djebbi-Simmons D, Alhejaili M, Janes M, King J, Xu W.Survival and inactivation of human Norovirus GII.4 Sydney on commonly touched airplane cabin surfaces.AIMS Public Health. 2020;7(3):574-586.Centers for Disease Control and Prevention.Burden of foodborne illness: findings.Centers for Disease Control and Prevention.Burden of Norovirus illness in the U.S.Switaj TL, Winter KJ, Christensen SR.Diagnosis and management of foodborne illness.Am Fam Physician. 2015;92(5):358-365.National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases.Treatment for food poisoning.Centers for Disease Control and Prevention.How to prevent Norovirus.MedlinePlus.Food poisoning.National Institute of Diabetes and Digestive and Kidney Diseases.Symptoms & causes of viral gastroenteritis (“stomach flu”).MedlinePlus.Dehydration.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
National Institute of Diabetes and Digestive and Kidney Diseases.Symptoms & causes of food poisoning.National Institute of Diabetes and Digestive and Kidney Diseases.Diagnosis of viral gastroenteritis (“stomach flu”).Centers for Disease Control and Prevention.About Norovirus.Centers for Disease Control and Prevention.Key facts about food poisoning.Centers for Disease Control and Prevention.About food safety.Djebbi-Simmons D, Alhejaili M, Janes M, King J, Xu W.Survival and inactivation of human Norovirus GII.4 Sydney on commonly touched airplane cabin surfaces.AIMS Public Health. 2020;7(3):574-586.Centers for Disease Control and Prevention.Burden of foodborne illness: findings.Centers for Disease Control and Prevention.Burden of Norovirus illness in the U.S.Switaj TL, Winter KJ, Christensen SR.Diagnosis and management of foodborne illness.Am Fam Physician. 2015;92(5):358-365.National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases.Treatment for food poisoning.Centers for Disease Control and Prevention.How to prevent Norovirus.MedlinePlus.Food poisoning.National Institute of Diabetes and Digestive and Kidney Diseases.Symptoms & causes of viral gastroenteritis (“stomach flu”).MedlinePlus.Dehydration.
National Institute of Diabetes and Digestive and Kidney Diseases.Symptoms & causes of food poisoning.
National Institute of Diabetes and Digestive and Kidney Diseases.Diagnosis of viral gastroenteritis (“stomach flu”).
Centers for Disease Control and Prevention.About Norovirus.
Centers for Disease Control and Prevention.Key facts about food poisoning.
Centers for Disease Control and Prevention.About food safety.
Djebbi-Simmons D, Alhejaili M, Janes M, King J, Xu W.Survival and inactivation of human Norovirus GII.4 Sydney on commonly touched airplane cabin surfaces.AIMS Public Health. 2020;7(3):574-586.
Centers for Disease Control and Prevention.Burden of foodborne illness: findings.
Centers for Disease Control and Prevention.Burden of Norovirus illness in the U.S.
Switaj TL, Winter KJ, Christensen SR.Diagnosis and management of foodborne illness.Am Fam Physician. 2015;92(5):358-365.
National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases.Treatment for food poisoning.
Centers for Disease Control and Prevention.How to prevent Norovirus.
MedlinePlus.Food poisoning.
National Institute of Diabetes and Digestive and Kidney Diseases.Symptoms & causes of viral gastroenteritis (“stomach flu”).
MedlinePlus.Dehydration.
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