Nosebleeds are not usually serious and can be stopped with home treatment. Most nosebleeds occur in the front of the nose (anterior epistaxis) and involve only one nostril. Some blood may drain down the back of the nose into the throat. Many things may make a nosebleed more likely.

• Changes in the environment. For example:
  • Cold, dry climates; low humidity
  • High altitude
  • Chemical fumes
  • Smoke
• Injury to the nose. For example:
  • Hitting or bumping the nose
  • Blowing or picking the nose
  • Piercing the nose
  • An object in the nose. This is more common in children, who may put things up their noses, but may be found in adults, especially after an automobile accident, when a piece of glass may have entered the nose.
• Medical problems. For example:
  • An abnormal structure inside the nose, such as nasal polyps or a deviated nasal septum
  • Colds, allergies, or sinus infections
  • High blood pressure
  • Kidney disease
  • Liver disease
  • Blood clotting disorders, such as hemophilia, leukemia, thrombocytopenia or von Willebrand's disease
  • Abnormal blood vessels in the nose, such as with Osler-Weber-Rendu syndrome. This syndrome is passed in families (inherited). The abnormal blood vessels make it hard to control a nosebleed.
• Medicines. For example:
  • Those that affect blood clotting, such as warfarin (Coumadin), heparin, Lovenox, Plavix, aspirin, and nonsteroidal anti-inflammatory drugs (NSAIDs)
  • Cold and allergy medicines
  • Oxygen
  • Nasal inhalers, such as Afrin
  • Steroid nasal sprays
• Nasal abuse of illegal drugs, such as cocaine and amphetamines

A less common but more serious type of nosebleed starts in the back of the nose (posterior epistaxis) and often involves both nostrils. Large amounts of blood may run down the back of the throat. Posterior epistaxis occurs more frequently in older adults because of other health conditions they may have. Medical treatment will be needed to control the bleeding from posterior epistaxis.

Review the Emergencies and Check Your Symptoms sections to determine if and when you need to see a health professional.