Repeated colds may be caused by frequent contact with cold and flu patients, frequent exposure to cold and flu, low immunity, overwork and so on. 1. Frequent contact with cold and flu patients: The cause of cold and flu is viral infection of the mucous membrane of the upper respiratory tract, which is mainly transmitted through the respiratory tract. Therefore, frequent contact with cold and flu patients may lead to infection through inhalation of droplets emitted from their respiratory tracts. 2. Frequent exposure to cold: exposure to cold is a major cause of colds, especially in the fall and winter seasons, when temperatures vary greatly and are low, so if you don’t pay attention to increasing or decreasing your clothing in a timely manner, it is easy to catch a cold again and again. 3. Low immunity: Suffering from certain diseases, long-term malnutrition, lack of exercise, long-term application of hormones, immunosuppressive drugs, etc., these conditions will lead to low immunity, reduced ability to resist viruses, and easy to recurring colds. 4. Overwork: prolonged physical labor, lack of sleep, excessive mental stress and other factors may also lead to recurrent colds. Repeated colds may also be caused by other diseases with symptoms similar to those of colds, such as rhinitis and nasopharyngeal carcinoma, etc. It is recommended to consult a doctor for a clear diagnosis.