The classification of nosebleeds is as anterior or posterior, depending upon the source of bleeding. The blood supply to the nose is derived from branches of the internal (anterior and posterior ethmoid arteries) and external carotid arteries (sphenopalatine and branches of the internal maxillary arteries). Bleeding usually occurs when the mucosa is eroded and vessels become exposed and subsequently break.
This is a companion discussion topic for the original article at https://patient.info/doctor/nosebleed-epistaxis-pro