How is influenza classified?

Influenza can generally be classified into types such as influenza A, influenza B, influenza C, simple-type influenza, and pneumonia-type influenza. The specific details are as follows:

1. Influenza A: Caused by the influenza A virus, which tends to mutate easily and can lead to global pandemics. Symptoms are usually severe, including high fever, headache, and muscle aches, with some patients potentially developing complications.

2. Influenza B: Caused by the influenza B virus, which mutates more slowly than influenza A. It typically causes localized outbreaks. Symptoms are similar to those of influenza A but are generally milder, with a lower incidence of complications.

3. Influenza C: Caused by the influenza C virus, which has weaker pathogenicity. It usually results in only mild upper respiratory symptoms, rarely causes epidemics, and most patients recover spontaneously without special treatment.

4. Simple-type influenza: The most common clinical type, primarily characterized by high fever, fatigue, sore throat, and cough. There are no significant complications, the illness lasts about 1–2 weeks, and patients usually recover smoothly with symptomatic treatment.

5. Pneumonia-type influenza: A more severe form, commonly seen in elderly individuals, children, and others with weakened immune systems. In addition to typical flu symptoms, patients may experience respiratory difficulties and chest tightness. Timely treatment is essential to prevent disease progression.

During peak flu season, preventive measures should be taken, such as wearing masks and frequent handwashing. Individuals experiencing symptoms should rest promptly and avoid crowded places. Those with severe symptoms or who belong to high-risk groups should seek medical attention early for antiviral treatment to reduce the risk of complications.