Cold & Flu Related Illnesses Flu vs. Stomach Flu: What Is the Difference? By Kristina Herndon, RN Updated on August 15, 2023 Medically reviewed by Renee Nilan, MD Print The seasonal flu and stomach flu are completely different illnesses. The flu is caused by the influenza virus and symptoms mostly involve the upper respiratory tract. The stomach flu, medically known as viral gastroenteritis, can be caused by a number of viruses and causes gastrointestinal problems, such as diarrhea and vomiting. This article covers the differences between the seasonal flu and the stomach flu. It discusses symptoms, treatment, and when to call a healthcare provider. Influenza Cough Congestion Body aches and pains Fever Exhaustion or fatigue Viral Gastroenteritis Vomiting Diarrhea Stomach pain and cramping Occasionally fever Influenza When your healthcare provider talks about the flu, they are referring to influenza, or the seasonal flu. This virus circulates and makes people sick during flu season each year, and it can be a very serious illness. When combined with pneumonia, it is one of the top 10 causes of death in the United States. Symptoms Influenza comes on suddenly and will make you feel terrible. The symptoms may last anywhere from two to 10 days and make it difficult to comfortably carry out daily tasks. The most common influenza symptoms include: CoughCongestionBody aches and painsFever or feeling feverish or chillsExhaustion or fatigueSore throatRunny or stuffy noseHeadachesFatigue (tiredness)Vomiting and diarrhea (more common in children than adults) Although most symptoms of the flu go away within four to seven days, the cough and tiredness can last for weeks. Most healthy people recover without any serious problems, but some people may develop complications or secondary infections. Verywell / Brianna Gilmartin Treatment If you think you might have the flu, especially if you are in a high-risk group, contact your healthcare provider as soon as possible to see if you might benefit from antiviral medications. If taken within the first 48 hours of the start of your symptoms, they can lessen the severity and shorten the duration of your illness. This means you won't feel quite as bad for as long as you would have if you hadn't taken the medication. The Flu Gastroenteritis The stomach flu is a completely different virus from the seasonal flu. As such, it cannot be prevented by getting a flu vaccination. The stomach flu is most often caused by norovirus, rotavirus, or a foodborne bacteria. Symptoms Stomach flu symptoms often include: VomitingDiarrheaStomach pain and crampingOccasionally fever In general, if an adult is sick with gastrointestinal symptoms, it is not influenza but viral gastroenteritis. However, in children, vomiting and diarrhea may occur with influenza. Stomach flu usually lasts for just a few days, but depends on what is causing it. Norovirus is the most common cause and symptoms typically last one to two days. Treatment Gastroenteritis, although it is miserable, is typically not as serious as influenza and usually resolves on its own. Vomiting usually lasts no longer than 24 hours; diarrhea may continue for several days after that. Stomach Flu When To Call a Healthcare Provider Reasons to call a healthcare provider differ for the flu and stomach flu. Influenza If you think you have the flu, call your healthcare provider right away, since antiviral medications will only be prescribed within 48 hours of symptoms. You should contact your healthcare provider right away if you experience: Difficulty breathingShortness of breathPersistent chest or abdominal painDizziness, confusion, or difficulty wakingSeizuresSevere muscle pain or weaknessWorsening cough or fever If you start feeling better for a few days and then develop worsening symptoms, this is a classic sign that you have developed a secondary infection. You may need different treatments depending on your diagnosis. Gastroenteritis With the stomach flu, adults should see a healthcare provider right away with any of these symptoms: Irritability or lack of energy Diarrhea lasting more than two days High fever (over 104 F) Vomiting often Six or more loose stools in a day Severe stomach or rectum pain Stools that are black and tarry or contain blood or pus Symptoms of dehydration If you are vomiting frequently and unable to keep fluids down, contact your healthcare provider. Summary Though commonly confused with one another, the flu and the stomach flu are different viruses and illnesses. Flu symptoms typically last longer than stomach flu symptoms. The flu mostly affects the upper respiratory tract, while the stomach flu causes gastrointestinal problems. If you suspect you have influenza, see your practitioner immediately for testing and treatment. If you suspect the stomach flu, watch out for signs of dehydration and call your healthcare provider if symptoms are severe or linger. 5 Sources Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. Centers for Disease Control and Prevention. Leading Causes of Death. Centers for Disease Control and Prevention. Flu Symptoms & Complications. Penn Medicine. Flu (Influenza). National Institute of Diabetes and Digestive and Kidney Diseases. Symptoms & Causes of Viral Gastroenteritis (“Stomach Flu”). Centers for Disease Control and Prevention. Norovirus illness: key facts. By Kristina Herndon, RN Kristina Herndon, BSN, RN, CPN, has been working in healthcare since 2002. She specializes in pediatrics and disease and infection prevention. See Our Editorial Process Meet Our Medical Expert Board Share Feedback Was this page helpful? Thanks for your feedback! What is your feedback? Other Helpful Report an Error Submit