What is the 24-Hour Flu?

Young woman sitting on floor, leaning against toilet bowl
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If you have ever come down with symptoms of the stomach flu, you or someone you know may have said something like "oh, I hope it's just a 24-hour flu." We say and hear comments like this all the time, but is there really such a thing as a 24-hour flu?

Truthfully, the "flu" (influenza) is a completely different virus from the illness that leaves us lying in the fetal position on the bathroom floor while we wait for the vomiting to pass.

Influenza is primarily a respiratory virus that comes on suddenly. It can cause vomiting and diarrhea, but these symptoms are rare in adults.

What most people are referring to when they say they have the "24-hour flu" is actually a stomach virus that causes vomiting and diarrhea. These symptoms can be caused by many different viruses and can last anywhere from a few hours to a week or more. How long it will affect you depends on what is causing the symptoms and your body's reaction to it.

24 Hour Stomach "Flu"

The stomach flu -- or gastroenteritis -- can last anywhere from 24 hours to 10 days. This is typically what affects people who say they had a 24-hour flu.

Symptoms of the stomach flu include:

  • Vomiting
  • Diarrhea
  • Fever
  • Stomach Cramps
  • Nausea
  • Fatigue or Exhaustion

Although the symptoms are horrible and it is very common, the stomach flu really isn't related to the flu at all. Viruses that cause the stomach flu include rotavirus, adenovirus, norovirus, sapovirus, and astrovirus, while the flu is caused by the influenza virus.

If you think you have this 24-hour bug, there are several steps you can take to help yourself feel better. Don't try to eat or drink anything too quickly if you are vomiting and pay attention to your other symptoms. Vomiting can be a sign of some very serious illnesses.

If you aren't sure what to do when you start vomiting, we have all the information you need. Step-by-step instructions will help get you on the road to recovery as quickly as possible.

Taking care of yourself properly when you have a stomach virus can go a long way toward helping you recover more quickly. Pay attention to your body and to your symptoms. Trying to "push through" your symptoms when you have a stomach bug will only prolong the illness.

The Actual Flu (Influenza)

By contrast, the actual flu -- or influenza -- typically lasts between 3 and 7 days. Influenza is primarily a respiratory illness. Although gastrointestinal symptoms, such as vomiting and diarrhea, can affect some people with influenza, they most often occur in children but very rarely in adults.

Symptoms of influenza include:

  • Cough
  • Congestion
  • Fever
  • Body Aches
  • Exhaustion/Fatigue
  • Headache

Influenza is a serious illness that lasts for longer than 24 hours and can lead to serious complications. It is not just a bad cold and shouldn't be blown off like it is. If you think you might have influenza, contact your health care provider to see which treatment options are best for you.

One instance in which influenza may not last as long as it typically would is if you had a flu vaccine.

Most people who get flu vaccines don't get the flu at all, but if they do, the symptoms are typically less severe and they don't last as long as they do in people who were not vaccinated. However, the illness still lasts longer than 24 hours.

If you have an illness that comes and goes within 24 hours, it probably wasn't truly the flu.


Viral Gastroenteritis. Division of Viral Diseases 25 Feb 11. National Center for Immunization and Respiratory Diseases. US Centers for Disease Control and Prevention. 12 July 12.

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