Although bone seems hard, it is actually living, growing tissue. Throughout your life, the body is constantly breaking down and removing old bone tissue, and building new tissue to replace it. Up to age 35, this process works pretty well. However, after age 35, you begin to lose bone more quickly than you can build it. The amount of bone in your skeleton starts to decrease.
Women generally have thinner and lighter frames, so they have fewer stores of bone mass.
They also lose bone mass rapidly after menopause. Osteoporosis progresses silently for many years, although fractures often do not develop until later in life. According to a National Institute on Aging study of a group of women, the rate of hip fractures rose between the ages of 40 to 44, and then continued at a constant rate of acceleration, doubling ever five or six years. By age 65 to 70, men and women lose bone tissue at about the same rate. Once considered a normal part of aging, we now know that osteoporosis is both preventable and treatable.