Osteoporosis
Osteoporosis, bone condition characterized by a decrease in mass, resulting in bones that are more porous and more easily fractured than normal bones. Fractures of the wrist, spine, and hip are most common; however, all bones can be affected. White females are the most susceptible, but other risk factors include low calcium intake; inadequate physical activity; certain drugs, such as corticosteroids, and a family history of the disease. The most common form of the disease, primary osteoporosis, includes postmenopausal (see Menopause ), or estrogen-deficient, osteoporosis (Type I), which is observed in women whose ovaries have ceased to produce the hormone estrogen; age-related osteoporosis (Type II), which affects those over the age of 70; and idiopathic osteoporosis, a rare disorder of unknown cause that affects premenopausal women and men who are middle-aged or younger. Secondary osteoporosis may be caused by bone disuse as a result of paralysis or other conditions, including weight