Membranes and blood vessels are really close to the surface. Nose bleeds come on more frequently while in dry conditions. By using a salt based nasal spray, you can help prevent the nose bleeds. I USED TO HAVE VERY FREQUENT NOSE BLEEDS WHEN I WAS A KID, AND IT STOPPED MINE COMPLETELY. I`m now 34 now and have not had a nose bleed in over 20!