A nosebleed, also called epistaxis, is a common occurrence for many individuals. The nose warms and moistens the air as the body breathes. The lining of the nose is rich in small blood vessels and any irritation or damage to the inside of the nose may cause bleeding. The most common cause of a nosebleed is a combination of dry air and nose picking. The dry air causes cracking in the skin and picking or blowing the nose causes the bleeding to occur. Additional conditions may also increase the possibility of a nosebleed.
Injury
Any trauma to the nose may cause bleeding. The injury may be a minor as scratching the lining with a fingernail or as major as a broken nose from an accident. Any foreign objects inserted into the nose may cause bleeding.
Nasal Irritation
Many conditions may cause irritation to the lining of the nasal passageway. Dry air is the leading cause of this irritation, according to the Mayo Clinic. Conditions such as heated air in the winter cause the dryness in the nose. Cold air is also irritating to the nose. Additional irritants include chemicals and pollen.
Medications
Several different types of medication may cause bleeding from the nose. Blood thinners--used for treating certain heart conditions--increase the possibility of bleeding from the tiny blood vessels in the nose. Using nasal sprays may also increase the possibility of irritation in the nose and cause bleeding.
Medical Conditions
Certain medical conditions increase the risk of bleeding in the nose. Individuals with high blood pressure, hardening of the arteries and blood clotting disorders all experience higher incidence of nosebleeds, according to the American Academy of Family Physicians. Nasal tumors and leukemia can also cause the bleeding.
Cocaine Use
Snorting cocaine up the nose causes the skin to thin out in the nose and can cause an erosion of the septum due to vasoconstriction of the blood vessels in the nose. Each of these conditions create causes for bleeding.
Pregnancy
Nosebleeds are common for pregnant women because of increased blood in the body. The excess blood places pressure on the blood vessels in the nose, sometimes causing a rupture in the nose.
