Question

Why do mountaineers usually suffer from nose-bleeding at high altitudes?

Answer 1

As the altitude increases the atmospheric pressure decreases. As the air becomes rarer percentage presence of oxygen also becomes less at high altitudes.In an effort to compensate for reduced oxygen the heart pumps fater creating pressure on the blood vessles .The capillaries present inside the nose bursts and starts bleeding. This is why mountaineers suffer from nose bleeding.