How does osteoporosis cause bone fractures?

Osteoporosis (a bone-thinning condition) increases the risk of fractures in every bone of the body. However, two types of osteoporotic fractures -- in the spine and hip -- can be particularly disabling.

In the spine, compression fractures can cause vertebrae to collapse. Multiple spinal compression fractures in a woman can lead to a medical condition called dorsal kyphosis, or "dowager's hump". The collapsed vertebrae may cause a downward curve in the spine and a loss in height between the shoulder and hip. As the length of the torso shrinks, the abdominal organs are crowded and pushed forward, leading to a host of discomforts, including breathing difficulties, digestive disorders, constipation, and urinary incontinence. Moreover, the changes can throw off your balance, making it more difficult to get around.

Hip fractures usually involve cracks in the head of the femur, or thighbone. Because these injuries usually occur later in life, the road to recovery can be difficult. Repair usually involves hip replacement and many weeks of recovery and rehabilitation treatments.

Osteoporosis causes bone to become porous and fragile. Over time, calcium leaches from the bone, lowering bone density and depleting its strength. The result is bone that is vulnerable to breaks. Osteoporosis contributes to more than two million bone fractures a year. Spinal, wrist, and hip fractures are most common, with hip fractures being the most serious of all.