Osteoporosis is caused by decreased bone mass resulting in fragile bones. Progressive osteoporosis may cause loss of height, stooped posture, a humpback (kyphotic curve), and severe pain. It commonly affects the thoracic and thoracolumbar regions of the spine and may cause debilitating pain. The structural deterioration of bone increases the risk for fracture in the hip, spine, and wrist.

The Osteoporosis and Related Bone Disease National Resource Center report that "Osteoporosis is responsible for more than 1.5 million fractures annually, including 300,000 hip fractures and approximately 700,000 vertebral fractures, 250,000 wrist fractures, and more than 300,000 fractures at other sites."

Normally associated with aging, osteoporosis contributes to fractures in older people. Many adults reach peak bone mass by age 30 - thereafter, small amounts of bone are naturally lost. This gradual reduction in bone density increases the risk for fracture. Spinal fractures (wedge, compression, burst) often affect one or more of the vertebral bodies. In some cases, the patient is unaware they have osteoporosis until fracture occurs. In severe osteoporosis, simple movements like bending, twisting, walking, or reaching can cause vertebrae to collapse.