How many days does fever last with influenza A and B?

Influenza A and Influenza B are both types of seasonal influenza, infectious diseases caused by influenza viruses that infect the epithelial cells of the respiratory tract, leading to respiratory infections. When someone contracts seasonal influenza, symptoms typically begin to appear and usually develop into high fever, headache, body aches, fatigue, cough, and runny nose within two to three days. The progression of the illness varies significantly—healthy individuals may experience only a few days of fever, while those with weaker immune systems may require a longer time to fully recover. Generally, high fever associated with Influenza A lasts 3 to 7 days, whereas high fever from Influenza B may last 7 to 10 days, depending on the individual's physical condition and immune system. It is recommended that patients avoid going out during periods of high fever and stay home to rest as much as possible to prevent worsening of the condition.