The phrase “24-hour flu” commonly describes a sudden, short-lived illness causing digestive upset. This term is often a misnomer, as the condition is typically not influenza, the virus responsible for respiratory flu.
Unpacking the “24 Hour Flu”
The “24-hour flu” is not influenza, a respiratory illness affecting the nose, throat, and lungs. Instead, it refers to viral gastroenteritis, an infection of the gastrointestinal tract known as a “stomach bug” or “stomach flu.” While the name implies a brief 24-hour duration, symptoms of viral gastroenteritis typically last one to three days, though they may occasionally extend up to 10 days.
True influenza, caused by the influenza virus, primarily affects the respiratory system with symptoms like fever, body aches, fatigue, cough, sore throat, and congestion. Viral gastroenteritis targets the digestive system, leading to symptoms in the stomach and intestines. The seasonal flu vaccine protects against influenza, not the viruses causing viral gastroenteritis.
Common Symptoms and Viral Culprits
The “24-hour flu” primarily involves the digestive system. Individuals experience nausea, vomiting, watery diarrhea, and abdominal cramps. Other symptoms include a low-grade fever, headache, or body aches. These symptoms usually appear within 12 to 48 hours after exposure.
Norovirus and rotavirus are the most common viral agents responsible for these symptoms. Norovirus is highly contagious and the leading cause of viral gastroenteritis in adults. It spreads through contaminated food, water, or direct contact with an infected person.
Rotavirus mainly affects infants and young children, though a vaccine is available. This virus spreads through contact with infected stool. Both viruses can be shed in stool even before symptoms appear and for a period after recovery, contributing to their easy transmission.
Home Care and When to Seek Help
Managing viral gastroenteritis at home focuses on preventing dehydration. Drinking plenty of fluids replaces those lost through vomiting and diarrhea. Clear fluids like water, clear broths, and oral rehydration solutions are recommended. Small, frequent sips help prevent further stomach upset. Rest is also beneficial, as the body needs energy to recover.
Once solid foods can be tolerated, a bland diet, like the BRAT diet (bananas, rice, applesauce, toast), may be helpful. These foods are easily digestible and help bind stools. Avoid foods that can irritate the stomach or worsen diarrhea, such as dairy products, greasy or fatty foods, and spicy dishes.
Most cases of viral gastroenteritis resolve on their own, but specific signs indicate a need for medical attention. Seek help for signs of severe dehydration, including decreased urination, dry mouth, dizziness, or a rapid heart rate.
Other concerning symptoms include vomiting or diarrhea that does not improve after a few days, bloody or black stools, severe abdominal pain, or a high fever, particularly in children. Infants, older adults, and individuals with weakened immune systems are at higher risk for severe dehydration and should seek medical care promptly.