Colds are inflammatory diseases of the upper respiratory tract caused by various viruses and bacteria. Normally, the natural course of a cold should be around 7-10 days, so if a cold lasts more than 20 days, it is definitely not normal. Colds that last for more than 20 days are caused by patients who are weak, immunocompromised, or have underlying medical conditions, such as diabetes, heart disease, kidney disease, or liver disease, and it is usually harder for them to get well from a cold. Also, seen as a complication of a cold, many people usually just have a runny nose and sneezing after a cold. If the physical condition is relatively poor, the cold may lead to pneumonia, myocarditis, or even meningitis and other conditions, resulting in the prolongation of the disease, so the cold is not good for more than 20 days, it is recommended to go to the hospital to check for the best.