Epistaxis is when blood comes out of the nose. It is more commonly known as a nosebleed. Even though nosebleeds can seem scary, they are usually not serious or life threatening. Most nosebleeds happen in the front of the nose, and these are called "anterior nosebleeds". Sometimes, people get nosebleeds in the back of their noses, called "posterior nosebleeds". These are more serious, and somebody who has one may have to go to the hospital.