How does osteoporosis make bones more fragile with age?

Osteoporosis, which literally means "porous bone," causes bones to become more fragile with age by disrupting the balance between bone formation and bone resorption. While bone mass naturally declines after reaching its peak in young adulthood, this process accelerates significantly in older individuals, particularly in women following menopause due to a decline in estrogen and other sex hormones.12

In healthy bone, a dynamic equilibrium exists where old bone is broken down and replaced by new tissue. In osteoporosis, this balance shifts so that resorption exceeds formation. Within the bone's honeycombed matrix, the tiny, rigid plates become thinner and rodlike, while the spaces between them grow larger. This structural change results in a significant decrease in bone mineral density, leaving the skeleton lighter and less capable of withstanding minor stresses or traumas. Consequently, bones become highly susceptible to fractures, which are a primary cause of morbidity and mortality in the elderly.3142