A nosebleed, also known as epistaxis ( EP-ih-STAK-sis), is the common occurrence of bleeding from the nose. It is usually noticed when blood drains out through the nostrils.
There are two types: anterior (the most common), and posterior (less common, more likely to require medical attention). Sometimes in more severe cases, the blood can come up the nasolacrimal duct and out from the eye. Fresh blood and clotted blood can also flow down into the stomach and cause nausea and vomiting.
Although the sight of large amounts of blood can be alarming and may warrant medical attention, nosebleeds are rarely fatal, accounting for only 4 of the 2.4 million deaths in the U.S. in 1999. About 60% of people have a nosebleed at some point in their life. About 10% of nosebleeds are serious. Nosebleeds appear to have a bimodal distribution, most commonly affecting those younger than 10 and older than 50.