Usually, patients have the most severe symptoms on the second to fourth day after the onset of a cold. Cold is short for upper respiratory tract infection and is a self-limiting disease, mostly related to a decrease in autoimmunity. Usually the cold cycle is about 7 days, and the symptoms are mild at the beginning of the cold, which may manifest as mild chills or elevated body temperature, and can be obvious on the 2nd-4th days, such as dizziness, headache, cough, phlegm, weakness of limbs, etc. The symptoms will gradually improve on the 4th-7th days after taking medication. The common viral cold can be cured by itself without medication, but elderly patients with underlying diseases must go to community hospitals or infection departments of regular hospitals promptly when they have cold symptoms. In addition, patients with cold symptoms and during treatment must also work and rest regularly, keep the air circulating, pay attention to warmth, eat more vitamin-rich and easy-to-digest food, drink more water, and do physical exercise to improve their immune system.