It is not recommended to lie down when having a nosebleed. Nosebleeds are caused by rupture of the mucous membrane and blood vessels in the nasal cavity due to various reasons, and the blood can flow to the front and back nostrils. When lying down, the blood will flow backward along the posterior nostril to the throat, thus causing the patient to experience an irritating choking cough. When the amount of bleeding is large, it will be swallowed into the stomach and intestines, thus causing the patient to experience nausea, vomiting and abdominal discomfort and other related symptoms. Therefore, it is not recommended that patients with nosebleeds lie down. If the nosebleed is occasional and the amount of bleeding is not large, it can be temporarily observed and relieved by pressing on the nose or applying cold compresses to the forehead. If the patient has frequent nosebleeds and the bleeding is large, it is recommended to go to the hospital in time and follow the doctor’s instructions for treatment to avoid delaying the condition.