What are the symptoms of infection with the influenza virus?

Generally, the term "influenza virus" refers to the influenza virus. Symptoms of infection with the influenza virus include cough, sore throat, fever, muscle pain, fatigue, and others. A detailed analysis is as follows:

1. Cough

The influenza virus primarily affects the upper respiratory tract, including the nasal cavity, pharynx, and larynx. When the influenza virus replicates in these areas, it causes mucosal inflammation and edema, stimulating the cough reflex and resulting in coughing.

2. Sore Throat

The influenza virus invades the pharyngeal mucosa. When the virus replicates in this area, it causes mucosal congestion, edema, and the release of inflammatory mediators, leading to throat pain that worsens during swallowing.

3. Fever

After entering the body, the influenza virus triggers an immune response. Immune cells attempt to eliminate the virus, and during this process, cytokines and other inflammatory mediators are produced, resulting in fever.

4. Muscle Pain

Toxins produced by the influenza virus can enter the muscle tissue through the bloodstream, causing muscle pain. Fever increases lactic acid production, which accumulates in the soft tissues, exacerbating muscle pain.

5. Fatigue

Following infection with the influenza virus, the body's immune system consumes significant energy to fight the virus. Additionally, viral replication and inflammatory responses can lead to a decline in bodily functions, causing the patient to feel fatigued.

However, it should be noted that the severity and duration of influenza symptoms may vary among individuals due to differences in physical condition. People should strengthen personal protection by wearing masks, washing hands frequently, and avoiding crowded places to reduce the risk of infection.