What condition is characterized by reduced bone density and an increased risk of fractures?

Osteoporosis is the correct answer as it is a medical condition specifically characterized by reduced bone density, which leads to bones becoming fragile and increasing the risk of fractures, particularly in weight-bearing areas such as the hips, spine, and wrists. This condition usually occurs quietly over many years, often without symptoms until a fracture occurs, making it a significant health concern, particularly among older adults.

In contrast, arthritis refers to inflammation of the joints, which may lead to pain and stiffness but does not directly affect bone density in the same way as osteoporosis. Fibromyalgia is a chronic condition characterized by widespread musculoskeletal pain, fatigue, and tender points, and does not involve changes in bone density. Rheumatism is a term historically used to describe pain and inflammation in the joints and muscles but is not a specific diagnosis and does not specifically indicate reduced bone density.