A nosebleed occurs when the membranes lining the inner nose are disturbed or irritated enough to cause abnormal bleeding. The medical term for nosebleed is epistaxis.
There are two types of nosebleeds: anterior and posterior. If the bleeding is near the front of the nose, it is an anterior nosebleed. A posterior nosebleed occurs in the back of the nose and is not always characterized by rapid bleeding but may be a slow, steady ooze. It may be more difficult to locate the site of the damage in a posterior nosebleed than in an anterior nosebleed. An anterior nosebleed is usually not as severe or serious as a posterior nosebleed.
If you have a nosebleed after a heavy blow to your skull, it could mean you have a fractured skull. You should go to the hospital immediately.
The most common causes of nosebleed are:
Symptoms of anterior nosebleed include intermittent or constant bleeding out of the front of your nose. Blood can flow from one or both nostrils and can flow into the throat.
Symptoms of posterior nosebleed include bleeding that stops and starts, rapid bleeding from the back of the nose, or a slow, steady ooze. Sometimes the blood flows back into your throat. Especially with posterior nose bleeding, you can lose blood quickly.
Some causes of nosebleeds can be prevented or managed as follows:
Nosebleeds may be treated by first aid, packing, cauterization, surgical procedures including reconstruction of the nasal septum and arterial ligation, and embolization.
These procedures are described in this section's page on Treatments for Nosebleeds
Additional information on Embolization for nosebleeds
Source: This page is adapted from a Nosebleed patient handout published by NICDC, online at http://www.nih.gov