Osteoporosis, which means "porous bones," causes bones to become weak and brittle - so brittle that even mild stresses like bending over, lifting a vacuum cleaner or coughing can cause a fracture. In most cases, bones weaken when you have low levels of calcium, phosphorus and other minerals in your bones. Osteoporosis can also accompany endocrine disorders or result from excessive use of drugs such as corticosteroids. A common result of osteoporosis is fractures, most often in the spine, hip or wrist. Although often thought of as a women's disease, osteoporosis also affects a significant number of men. Your risk of developing osteoporosis depends on how much bone mass you attained between ages 25 and 35 (peak bone mass years) and how rapidly you lose that mass later. The higher your peak bone mass, the more bone you have "in the bank" and the less likely you are to develop osteoporosis as you age.

Calcium and vitamin D supplementation are the cornerstone of treatment. Weight-bearing exercise, smoking cessation, minimizing alcohol and balance training can also help reduce fracture risk. There are two main classes of pharmacologic agents used for osteoporosis: bisphosphonates (such as Actonel or Fosamax) which decrease the breakdown of bone and anabolic agents (such as Forteo) which actively build new bone.