However, if the body is given plenty of time to adapt, then most people can cope well at altitudes up to atleast 5000 metres

As the body gradually acclimatises to high altitude, a number of changes take place.

The number of red blood cells increases: whereas red blood cells normally make up about 40-50% of the blood, after a few months at high altitude this rises to as much as 50-70%. However, it takes time. There is no change in the number of red blood cells for atleast two or three weeks at high altitude.

People who live permanently at high altitude often have especially broad chests, providing larger lung capacities than normal.
The heart is often larger than in a person who lives at low altitude, especially the right side, which pumps blood to the lungs.
They also have more haemoglobin in their blood than usual, so increasing the efficiency of oxygen transport from lungs to tissues.

	Criado por Aarushi Pandit quase 9 anos atrás

An elucid, brief note on the effects of high altitude on oxygen transport