Any bone can be affected by osteoporosis, but the hips, wrists and spine are the most common sites. Peak bone mass is reached between the ages of 25 and 35 years. After 35, everyone's bones lose density. The actual causes of osteoporosis are unknown. Certain risk factors, however, increase the likelihood of developing osteoporosis.
Women are four times more likely to develop osteoporosis than men.
Women live longer than men. Women experience rapid bone loss at menopause due to a sharp decline of estrogen. Lack of physical activity, especially walking, running, tennis and other weight-bearing exercises or, exercising excessively to the point where menstrual periods cease. Lack of calcium. Adequate calcium intake throughout life helps to prevent calcium deficiency that contributes to a weakening of bone mass.