Causes

The lining of your nose contains many tiny blood vessels that lie close to the surface and are easily irritated.

The two most common causes of nosebleeds are:

• Dry air � when your nasal membranes dry out, they're more susceptible to bleeding and infections
• Nose picking

Other causes of nosebleeds include:

• Acute sinusitis (nasal and sinus infection)
• Allergies
• Aspirin use
• Bleeding disorders, such as hemophilia
• Blood thinners (anticoagulants), such as warfarin and heparin
• Chemical irritants, such as ammonia
• Chronic sinusitis
• Cocaine use
• Common cold
• Deviated septum
• Foreign body in the nose
• Nasal sprays, such as those used to treat allergies, if used frequently
• Nonallergic rhinitis (chronic congestion or sneezing not related to allergies)
• Trauma to the nose

Less common causes of nosebleeds include:

• Alcohol use
• Hereditary hemorrhagic telangiectasia
• Immune thrombocytopenia (ITP)
• Leukemia
• Nasal and paranasal tumors
• Nasal polyps
• Nasal surgery

In general, nosebleeds are not a symptom or result of high blood pressure.