Osteopetrosis is a rare bone disorder characterized by the abnormal density of bones. In this condition, the bones become overly dense and hard due to a defect in the cells that break down bone tissue, known as osteoclasts. This can lead to brittle bones that are more prone to fractures, despite their increased density. Symptoms of osteopetrosis may include bone pain, frequent fractures, and complications such as anemia or nerve compression. The condition can be inherited and varies in severity, with some forms appearing in childhood and others in adulthood. Treatment options may involve medications, surgery, or bone marrow transplants.