Causes

Dry, cold air during the winter can cause nosebleeds, as can indoor air that causes your nasal membranes to dry out and become overly fragile. This increases the risk of nosebleeds due to broken blood vessels. Colds and sinus infections can also cause nosebleeds, when inflammation in the nasal passages damages blood vessels. Blowing your nose too hard can trigger a nosebleed. Other causes include respiratory allergies, trauma to the nose, inhaling irritating chemicals and medications that thin blood. Occasionally, nosebleeds signal an underlying condition like high blood pressure, a blood-clotting disorder or polyps or other abnormal growths within your nose.

Prevention

Increase the humidity of your indoor environment by using humidifiers. Help keep your nasal passages moist by dabbing a small amount of petroleum jelly inside each nostril once a day. Use saline nose drops to prevent dry nasal passages. Prevent catching colds by washing your hands frequently. If you have a cold, blow your nose softly to prevent damage to the blood vessels within your nose.

Home Remedies

Cover your nose with a tissue and pinch the end of your nose. Tilt your head forward and wait five minutes before checking to see if the flow has stopped. Tilting your head backward will cause the blood to run down the back of your throat, triggering a gagging reflex. You can also apply a cold compress to the bridge of your nose to help stop the bleeding faster.

Medical Treatment

Chronic heavy bleeding needs to be treated by a doctor. One treatment is to cauterise the damaged blood vessel with heat or silver nitrate, sealing it. The health-care provider can also pack gauze inside the nostril until the bleeding stops. The doctor may reduce your use of blood-thinner medications or help you control an underlying medical condition such as high blood pressure.

Risk Groups

Adults at risk for chronic nosebleeds may have a deviated septum, frequent colds, respiratory allergies, exposure to dry air and repeated trauma to the nose. Other risk factors include having a foreign object in the nose, nose picking and breathing in irritating chemicals. Use of medications like Coumadin or non-steroidal anti-inflammatory drugs (NSAIDs) can weaken the strength of blood vessels. People who have hereditary hemorrhagic telangiectasia---a rare vascular disorder---are also at increased risk for chronic nosebleeds.