A height loss of about 4 cm or more with advancing age can be a sign of decreased bone mass (osteoporosis).
The reduction in bone density makes the vertebrae increasingly brittle so that they eventually collapse.
Bone fractures with no apparent cause or which occur during everyday activities or exercise, a rounded back ("Witwenbuckel") ("dowager's hump") and constant pain in the lumbar or thoracic spine are signs of the possible development of osteoporosis. Fractures of the femoral neck (thigh bone) through minor falls and broken wrists on putting out a hand to save a fall are common. Ribs can even fracture when coughing.