What is the primary effect of osteoporosis on bones?

Osteoporosis primarily leads to a decrease in bone density, making bones soft and brittle. This condition occurs when the body loses too much bone mass or fails to create enough new bone tissue, resulting in bones that are more susceptible to fractures and breaks. Individuals with osteoporosis may experience serious complications from falls or minor injuries due to the weakened state of their bones.

The other choices do not accurately reflect the effects of osteoporosis. Strong and dense bones, for instance, are typically associated with healthy bone maintenance and density, which is the opposite of what occurs in osteoporosis. Heavier bones and an increase in size also do not align with the condition, as osteoporosis leads to decreased mass and density rather than enlargement. Thus, the correct understanding is that osteoporosis causes bones to become soft and brittle, significantly impacting overall skeletal health and stability.