This item tests understanding of osteoporosis, a disease characterized by low bone mass and deterioration of bone tissue. In osteoporosis, bone mineral density is reduced and the microarchitecture of bone becomes progressively disrupted, making bones fragile and prone to fractures with little or no trauma. Osteopenia describes reduced bone mass without the same level of architectural breakdown, so it isn’t as strongly linked to fragility. Rickets affects growing bones in children due to vitamin D deficiency and results in defective mineralization and deformities, not primarily a loss of bone mass. Osteomalacia is the adult form of defective mineralization, causing bone pain and fractures, but the central issue is mineralization rather than the structural deterioration seen in osteoporosis.