Why does osteoporosis make bones more likely to fracture after minor stresses?

Osteoporosis, which literally means "porous bone," increases the risk of fractures because it fundamentally alters the internal structure of bone tissue. In healthy bone, a honeycombed matrix of rigid plates provides structural support. In individuals with osteoporosis, these plates become thinner and rodlike, causing the spaces between them to enlarge.1

This structural degradation occurs due to an imbalance in the body's natural bone remodeling process, where the rate of bone resorption (breakdown) exceeds the rate of new bone formation. As a result, the bone becomes significantly less dense and more fragile. Because there is less bone per unit volume, the skeletal structure loses its ability to withstand mechanical forces. Consequently, bones become susceptible to fracturing from minor traumas or stresses that would typically have no effect on a healthy, denser skeleton.1