Why Does One’s Nose Bleed when Visiting High Altitudes?

https://outdoorsfaqs.com/why-does-ones-nose-bleed-when-visiting-high-altitudes/
There are several reasons for nosebleeds that all act simultaneously when you are in high mountains. They include the following:
Elevation.
Cold weather.
Low humidity.
As you realize all these effects are completely inter-related. But nosebleed is not necessarily a symptom of altitude sickness. This is a much milder reaction of our body to the combination of the effects mentioned above.