Nosebleeds result from broken blood vessels due to the membranes that line the nose becoming dried out or irritated. They are more common in the winter when the air is dry. Other factors are colds, allergies, sinus infections, blowing the nose too hard, or nasal fractures. Most nose bleeds occur in the front of the nose. These are characterized by anterior nosebleeds which are easy to control and do not pose a problem. Posterior nose bleeds are rare, but more serious. They originate from an artery in the back of the nose, and require immediate hospitalization and treatment. This is more common in the elderly.