Colds can be caused by bad habits or low immunity. 1. Bad habits: If you don’t pay attention to your body’s warmth, don’t add more clothes in time when the weather cools down, and don’t cover up when you go to bed at night, which causes your body to get cold, it is easy to cause colds. In addition, too tired, often stay up late, long time emotional depression, etc. is also easy to cold reasons. 2. Poor immune system: Some people are weak, have diabetes and other underlying diseases, or take immunosuppressants and other conditions that affect the immune system, resulting in the body’s resistance to viruses is relatively weak, and it is easy for viruses to invade and reproduce, so it is easy to catch a cold. It is recommended to pay attention to keep warm, eat healthily, live regularly and strengthen exercise. If there is any underlying disease, actively control the underlying disease. In addition, cold symptoms, such as recurrent runny nose, may also be caused by allergic rhinitis and other diseases. Therefore, if the cold is recurrently bad, we should go to the regular hospital in time to clarify the cause of the disease and follow the doctor’s instructions to adopt the appropriate treatment program to avoid delaying the condition.