It’s the kind of illness that seems to come out of nowhere—you’re feeling fine one moment, and the next, you’re hit with nausea, stomach cramps and a general sense of misery. The 24-hour flu, though short-lived, can still disrupt your plans and leave you wondering what just happened. Contrary to its name, this condition isn’t caused by the influenza virus and isn’t technically the flu at all. We spoke with Robert Biernbaum, DO, the Chief Medical Officer at WellNow Urgent Carebetter to understand what the 24-hour flu is, how to treat it and ways to avoid it altogether.
What is the 24-hour flu?
The 24-hour flu, or viral gastroenteritis, is an infection that affects the stomach and intestines. “[It] usually refers to norovirus, which causes digestive issues such as nausea, vomiting and diarrhea, and typically clears up within 24 to 48 hours,” explains Dr. Biernbaum. “People call it the ‘24-hour flu’ since it can come and go quickly. While the symptoms are unpleasant, the good news is that most cases are mild and resolve within one to three days.
Dr. Biernbaum points out that while this condition is often called a “flu,” it has no connection to influenza. “The ‘regular’ flu is also caused by a virus, but it lasts longer—anywhere from five to seven days—and presents more as respiratory symptoms such as sore throat, cough, fever and chills.” The confusion likely stems from the rapid onset of symptoms and the fact that both illnesses are more common during colder months.
Similarly, the 24-hour flu shouldn’t be mistaken for food poisoning. Dr. Biernbaum says that “the major difference is that [the 24-hour flu] is caused by a virus and not contaminated food or drink.”
What causes it?
Viral infections, including norovirus or rotovirus, most often cause the 24-hour flu. “Norovirus is highly contagious,” and can lead to outbreaks in crowded or communal environments like nursing homes, cruise ships or schools,” says Dr. Biernbaum. “It spreads through infected surfaces, contaminated food or water or direct contact with [an infected individual].”
24-hour flu symptoms
Symptoms of the 24-hour flu typically appear suddenly and can include:
“Patients can sometimes experience fever, headache and body aches, but stomach-related symptoms are most common,” says Dr. Biernbaum. “Because of these symptoms, the body is able to flush out the virus more quickly than the traditional flu.”
For most people, these symptoms usually subside within a day or two, though it’s not uncommon to feel fatigued for a few days afterward. Additionally, severe dehydration can occur, particularly in older adults and those with weakened immune systems or certain underlying health issues.
How to treat the 24-hour flu
“There is no specific treatment for Norovirus, as symptoms typically clear up on their own,” assures Dr. Biernbaum. Treatment instead focuses on managing symptoms at home and preventing dehydration. Dr. Biernbaum recommends “plenty of rest and lots of fluids to stay hydrated, especially if you are experiencing vomiting and diarrhea.”
Other self-care steps you can take to manage symptoms include: the following:
- Stay hydrated: Oral rehydration solutions or electrolyte drinks like Pedialyte can be especially helpful.
- Eat bland foods: Once nausea subsides, opt for bland, digestable foods like bananas, rice, applesauce and toast (the BRAT diet).
- Rest: Allow your body to recover by getting plenty of sleep and avoiding strenuous activities.
- Try OTC meds: Over-the-counter remedies like anti-diarrheal medications or acetaminophen can provide relief, but be sure to consult your doctor before using them.
Most cases of the 24-hour flu resolve on their own, but there are times when medical care is necessary. “Contact a medical provider if your symptoms don’t start improving within 24 hours,” advises Dr. Biernbaum. Older adults and those with chronic health conditions should be particularly mindful, as they’re at a higher risk for complications.
Other severe symptoms to watch out for include:
- Persistent vomiting or diarrhea lasting more than one day
- Severe dehydration symptoms like dry mouth, sunken eyes or reduced urination
- Blood in stool or vomit
- A high fever above 102°F
How to reduce your risk of catching the 24-hour flu
Preventative measures can significantly reduce your risk of catching the 24-hour flu. “The best way to prevent illness is to wash your hands frequently and avoid sharing food and beverages with others,” reminds Dr. Biernbaum. Additionally, he recommends disinfecting all household surfaces regularly, “including door knobs, cell phones and other high-touch surfaces. If you feel sick, it’s best to stay home and avoid contact with others until your symptoms resolve.
This content is not a substitute for professional medical advice or diagnosis. Always consult your physician before pursuing any treatment plan.
