Common causes of frequent nosebleeds in adults are as follows: 1. Excessive dryness and congestion of the mucous membrane in the nasal cavity, possibly combined with inflammatory infections of the nasal cavity and sinuses and allergic diseases, which may cause local erosion, rupture and recurrent bleeding of the nasal mucous membrane; 2. Significant deviation of the nasal septum; 3. Bleeding-prone growths such as haemangiomas, haemorrhagic polyps and papillomas in the nasal tract, which may cause frequent nosebleeds; 4. Systemic diseases, including hypertension, diabetes, liver and kidney diseases, haematological diseases, etc. If necessary, the patient needs further examination by nasal endoscopy and examination of the relevant systems of the body to clarify the diagnosis.