Lung infections are infectious diseases of the lungs caused by a variety of germs such as bacteria viruses mycoplasma and even certain specific germs such as fungi. It may occur when the immune system is low, by mistake, by being infected by other people, or for other reasons.
1. Onset when immunity is low: for example, after overwork and heavy drinking, the autoimmunity is lowered and germs that colonize the respiratory tract may multiply rapidly and cause lung infections.
2. Misaspiration: For example, cerebrovascular disease swallowing dysfunction can lead to aspiration pneumonia.
3. Infection by other people: For example, pneumonia caused by influenza virus may be caused by contact with influenza patients.
4. Other reasons: for example, airway obstruction caused by foreign bodies in the airway or lung tumors may also lead to lung infections.
To summarize, lung infections can occur for a variety of reasons.