Osteoporosis - What Happens
In a normal, healthy adult, bone is constantly absorbed into the body and then rebuilt. During childhood and the teen years, new bone tissue is added faster than existing bone is absorbed. As a result, your bones become larger and heavier until about age 30 when you reach peak bone mass (density). The more bone mass you developed early in life, the less likely you are to get osteoporosis.
After age 30, people lose a small amount of bone each year.
A person with thinning bones may be diagnosed with lower-than-normal bone mass (osteopenia). Osteopenia sometimes progresses to osteoporosis.
When bones thin, they lose strength and break more easily. The bones that break most often due to osteoporosis are:
The spine . About half of broken bones caused by osteoporosis are bones in the spine.1 Vertebrae that are weak because of osteoporosis may break and collapse on top of each other. (This is called a compression fracture.) These fractures of the spine can cause back pain, stooped posture, loss of height, and a curved upper back (dowager's hump).
The hip. Hip fractures are often caused by a fall. They can make it very hard for you to move around. And they usually require major surgery. After a hip fracture, you may have medical complications such as blood clots, pressure sores, or pneumonia. To learn more, see the topic Hip Fracture.
The wrist and forearm. Wrist fractures can make you less active and independent.2
In women, bone loss increases when the ovaries reduce production of estrogen, a hormone that protects against bone loss.