Colds that do not go away can be caused by insufficient medication regimen, decreased resistance and underlying diseases. 1. Insufficient medication: If the patient does not follow the doctor’s instructions to take the medication on time and in accordance with the dosage, for example, stop taking the medication when the symptoms of the cold get better, and do not go for further consolidation of the treatment, then it will lead to the situation that the cold can not be cured. 2. Decreased resistance: Some people may have decreased resistance, and if their bodies are attacked by pathogenic bacteria for a long time, they may have bad colds. 3. Existence of underlying diseases: In addition, some people with underlying diseases may also suffer from colds. For example, AIDS and other diseases that can destroy the body’s immunity. Therefore, if you have a bad cold for reasons other than yourself, you should go to the hospital in time for treatment.