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

The two most common causes of nosebleeds are:

  1. Dry air — when your nasal membranes dry out, they're more susceptible to bleeding and infections
  2. Nose picking

Other causes of nosebleeds include:

  1. Acute sinusitis
  2. Allergies
  3. Aspirin use
  4. Blood thinners (anticoagulants), such as warfarin and heparin
  5. Chemical irritants, such as ammonia
  6. Chronic sinusitis
  7. Cocaine use
  8. Common cold
  9. Deviated septum
  10. Foreign body in the nose
  11. Nasal sprays, such as those used to treat allergies, if used frequently
  12. Nonallergic rhinitis
  13. Trauma to the nose

Less common causes of nosebleeds include:

  1. Alcohol use
  2. Hemophilia
  3. Hereditary hemorrhagic telangiectasia
  4. Idiopathic thrombocytopenic purpura (ITP)
  5. Leukemia
  6. Nasal polyps
  7. Nasal surgery
  8. Nasal tumor
  9. Sarcoidosis

Studies haven't confirmed an association between high blood pressure and nosebleeds. Some specialists suggest that high blood pressure may prolong bleeding if you have a nosebleed.

Causes shown here are commonly associated with this symptom. Work with your doctor or other health care professional for an accurate diagnosis.

Aug. 10, 2012