Cold is a common respiratory disease caused by a variety of viruses, which is generally divided into common cold and influenza. What we usually call is common cold, commonly known as cold. Colds are mostly caused by people catching a cold, and they begin with dryness, itching, and burning sensation in the nasopharynx, followed by sneezing, nasal congestion, runny nose, tears and other symptoms. After 1-2 days, it may be accompanied by sore throat, cough, or fever, headache, body aches, loss of appetite, or nausea, vomiting, diarrhea and other symptoms. If there are no complications, it can be cured in 5-7 days. Regardless of age, you can catch a cold all year round, but it is more common in autumn and winter when the temperature changes significantly. Generally, each person can catch a cold 2-5 times a year, and the number of colds will increase for children, the elderly and people with poor physical fitness.