The Difference Between Seasonal Flu and Stomach Flu

The Difference Between Seasonal Flu and Stomach Flu

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People often confuse the flu and stomach flu, but they are actually two completely different and unrelated 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. Though both commonly called the flu, influenza and the stomach bug are caused by different viruses and have different symptoms:

Influenza

  • Cough
  • Congestion
  • Body aches and pains
  • Fever
  • Exhaustion or fatigue

Viral Gastroenteritis

  • Vomiting
  • Diarrhea
  • Stomach pain and cramping
  • Occasionally fever

Influenza

When your doctor talks about the flu, he is referring to influenza, or the seasonal flu. This virus circulates and makes people sick during flu season each year. 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.

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 continue on with your life. The most common influenza symptoms include:

  • Cough
  • Congestion
  • Body aches and pains
  • Fever
  • Exhaustion or fatigue

Although most healthy people recover from the flu without any serious problems, some people may develop complications or secondary infections. If you have the flu, start feeling better for a few days and then develop worse symptoms with a higher fever, contact your health care provider. This is a classic sign that you have developed a secondary infection. You may need a different treatment depending on your diagnosis.

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. Meaning you won’t feel quite as bad for as long as you would have if you hadn’t taken it.

Gastroenteritis

The stomach flu is a completely different virus from the seasonal flu. It is most often caused by norovirus, rotavirus, or a food-borne bacteria and is characterized by:

  • Vomiting
  • Diarrhea
  • Stomach pain and cramping
  • Occasionally 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.2

Gastroenteritis, although it is miserable, is typically not as serious as influenza. You may need to seek medical attention if you are dehydrated. Vomiting usually lasts no longer than 24 hours. Diarrhea may continue for several days after that. If you are vomiting frequently and unable to keep fluids down, contact your healthcare provider.

A Word From Verywell

Though commonly confused for one another, the flu and the stomach flu are different viruses and illnesses. If you suspect you have influenza, see your doctor immediately for testing and treatment. If you suspect the stomach flu, watch out for signs of dehydration and call your doctor if symptoms linger.