Why does altitude change affect arthritis?

Experience at 8200 feetI'm afraid I don't know why altitude helped my Arthritis, but after just camping for two weeks in the Big Horn Mountains near Buffalo, Wyoming, at about 8200 feet, I can say with certainty that it did.

At home, near St. Louis, Mo which is at about 650 feet, I regularly experienced pain in my neck and back and frequently in my knee and hands. After the first week in the mountains, I noticed that I was waking pain free and able to go hiking without any discomfoort. It was great!

The first night out of the mountains we stayed at around 1400 feet. I woke that night with all of my joints hurting. Now at home it is just back to before we left.

I wonder if moving to the mountains would alleviate my pain permanently?