why do some people nose bleed after climbing mountains?

Question: why do some people nose bleed after climbing mountains?
- Keywords:
  blood,
  mountain,
  nose
Asked by aabb266 to Beatrice, Charles, George, Kamal, Patricia on 17 Jan 2017.
- George Githinji answered on 17 Jan 2017:
  
  It has to do with atmospheric pressure. As you climb up the air pressure gets low and the pressure within your body is slightly higher. This causes the small vessels and capillaries to burst leading to nose bleeding.
  
  Would you imagine what would happen if the aeroplanes are not pressurised?