There are two types of nosebleed - upper and lower. Most are lower, which means that they start in the lower part of the septum. The septum is the semi-rigid wall that separates the two channels of the nose. It contains blood vessels that can be broken by a blow to the nose or the edge of a sharp fingernail. They can usually be treated easily at home and do not require medical attention.
Upper nosebleeds are more rare.
They start when bleeding begins high and deep within the nose. Blood flows down the back of the mouth and throat even when the patient is sitting up or standing. This more severe type of nosebleed needs immediate medical attention. Nosebleeds are caused by the rupture of a small vessel in the nose due to pressure in the head. The other main cause is dryness of the inside of the nose.