Oxygen dissociation curve

Can anyone explain why does the oxygen dissociation curve shift to left in organisms living at high altitude?

At high altitude there is a low partial pressure of oxygen. In response to this, there is a shift to the left at higher altitudes because haemoglobin will have a higher affinity for oxygen. This means it will be able to quickly associate with O2 at a low O2pp/readily saturate itself.

Reply 2

Hayaalderi

But doesn’t increasing Hb affinity to oxygen makes it difficult to release oxygen to respiring tissues. So how shifting curve to the left is beneficial?

Reply 3

totallyfine

It does , this is the down side of shifting the curve. However, increasing carbon dioixide levels in respiring tissues will also encourage oxygen dissociation