Blood in the nose may be caused by fire, or by diseases such as repeated nose-picking and inflammatory bleeding. Blood in the nose is a common clinical symptom. Blood in the nose in children is usually caused by dry nasal mucosa, which is prone to injury and bleeding. Occasional blood in nasal snot in adults may be caused by repeated digging of nostrils, eating spicy and irritating food, etc., which may lead to damage to the mucous membrane of nasal vestibule and exposure of blood vessels outside the mucous membrane, which can lead to blood in nasal snot with a slight touch or blowing of nose. If there is blood in the nose repeatedly, you should be alert to the presence of nasal tumor and need to confirm the diagnosis by nasal endoscopy and CT examination. Patients with bloody nose need to maintain hygiene, pay attention to warmth, avoid dry air, eat nutritious food, avoid spicy diet, keep bowel movement smooth, and do not pick nose indiscriminately.