When the nose is dry and hard inside, the mucous membrane in the nasal cavity will secrete less snot. When the dust and impurities from the outside world mix with the nasal mucosa when breathing, it will easily stick to the mucosa of the nasal cavity and form a hard dry crust. When picking the nose to remove the dry crust, the nasal mucosa will be torn off, and in serious cases, there will be nasal snot with blood or nasal crust with blood. The main method of treatment is to moisten the nasal cavity with saline or to spray the nose with nasallon. After moistening the nasal cavity, the dry crusts will become soft and will easily fall off from the nasal mucosa on their own, and will be discharged out of the nasal cavity when blowing the nose or nasal rinsing. It is recommended to drink more water if you have a dry nose and hard nasal crust, try not to stay in a dry environment for a long time, and keep the environment you live in with a certain amount of humidity. In addition, the nasal cavity can be moistened with vitamin AD drops to keep the nasal mucosa moist. Diet is prohibited to eat spicy and stimulating food, smoking and drinking alcohol.