The causes of summer nosebleeds include: vitamin deficiency, nasal dryness, nasal septum deviation. 1. Vitamin deficiency: summer weather is hot, easy to cause gastrointestinal disorders, reduce vitamin intake, nasal mucosal metabolism abnormalities, resulting in mucosal coagulation mechanism due to dry heat damage to play a role in the obstruction of the nosebleed can be produced. 2. Nasal dryness: high temperature in summer, nasal airflow acceleration, mucosal secretion can not keep up with the speed of water evaporation, nasal mucosal dryness, mucosal cracking and bleeding. 3. Nasal septum deviation: Nasal septum mucous membrane deviation, especially the puffed up place and the tip of sphenoid mucous membrane is thin, in the high temperature and dry environment is very easy to break and bleed. When you have frequent nosebleeds in summer, you need to go to the hospital in time to avoid delays.