The nose is composed of three parts: the external nose, the nasal cavity and the paranasal sinuses. The health of the nose is very important to a person. This entry starts with the structure of the nose, briefly describes the various symptoms and causes of nose disease, and details post-nasal treatment, prevention and health care in daily life and other issues. Some patients often put forward the theory of fighting poison with fire, that is, after bathing in cold water or swimming in a cold pool, the body is less afraid of the cold, and they will try to rinse the nose with cold water, hoping to improve the sensitivity of allergic rhinitis to temperature differences. However, just like morning swimming in winter, this needs to be done gradually.