Why is it that anabolic steroids cause bone loss and osteoarthitis?

Bone resorption: Steroids cause an alteration in the normal equilibrium of bone production and bone resorption. The steroids actually affect this process not only by causing increased bone resoption but also by causing increased mechanical stress and strain on the bone from non physiologic increase in muscle mass over bone strength.

NO: Anabolic steroid, when taken early (and abusively) in teens, cause the bone to be harden and dense thus preventing the teenager reaches his or her full height. In adult, it affects your liver (when abused) and may cause liver cancer. I raise LDL (should be low) and lower HDL (should be high) and increased risk of heart disease. It does not cause bone loss or osteoarthritis.