What Is a disease on which bones become fragile and more likely to break?

The disease you're referring to is osteoporosis. It is a condition characterized by a decrease in bone density and quality, leading to increased fragility and a higher risk of fractures, particularly in the hip, spine, and wrist. Osteoporosis often develops silently over many years, making early detection and prevention crucial through lifestyle changes, such as adequate calcium and vitamin D intake, and regular weight-bearing exercise.