Simple things first. Prevention for nose bleeds consist of making sure the nasal membranes do not dry out. One can do this by routinely using a saltwater mist spray or apply a saltwater gel (aryl gel) both available otc. One can even use vaseline 2-3x a day. But vaseline should not be used for those on oxygen therapy. If nose bleeds persist then they should be evaluated.
Nose bleeds. Rarely this is caused by a blood clotting disorder (due to medications, liver problems, congenital etc.) and more commonly caused by dry nasal mucosa or rich capillary bed in the nasal septum. Start by using daily saline to keep mucosa moist and hydrate well. If this does not help, discuss with your physician to rule out underlying blood problem and procedures such as cauterization.
Watch this. Pinch the nose till the bleeding stops. Here is a video with more info for you http://www. Youtube. Com/watch? V=dp_i-gja7ui if things aren't better in a few weeks or if you have easy bruising or bleeding gums call your doctor.
Dry air. This is could drying of the nasal membrane, exposing the mucosa. There the small blood vessels of the septum dry and crack causing nose bleeds. Also rubbing and picking the nose wi;l do the same. Keep the nose moist.