Do flu patients experience a runny nose?

　　Influenza refers to the flu. In most cases, individuals with influenza may experience a runny nose; however, some patients with stronger immune systems might not develop this symptom. If you have concerns, it is recommended to consult a physician. A detailed explanation is as follows:

　　After the body is infected with the influenza virus, the immune system is immediately activated. The influenza virus invades the epithelial cells of the respiratory tract mucosa, multiplies extensively, and triggers an inflammatory response, causing congestion, swelling, and disordered secretion functions in the respiratory mucosa. To combat these viruses and inflammatory products, the mucosal glands within the nasal passages accelerate mucus secretion. Initially, the mucus is thin and drains from the nose, causing a runny nose. As the illness progresses, if a bacterial infection occurs as a complication, the nasal discharge may become thickened and yellow.

　　Some patients infected with the influenza virus may possess strong immune defenses that quickly and effectively suppress the spread of the virus, limiting its damage to the respiratory mucosa to a small area. This may prevent significant mucosal congestion, swelling, and abnormal mucus secretion, thereby possibly avoiding a runny nose. These patients may only exhibit other typical flu symptoms such as fever, headache, and fatigue.

　　In daily life, it is important to maintain good indoor air circulation by regularly opening windows for ventilation, which helps reduce viral concentration and lower the risk of infection.