Osteogenesis imperfecta is a genetic bone disease that causes severe fragility, making the bones susceptible to fracturing, MedlinePlus explains. People with osteogenesis imperfecta often have a short stature, hearing loss, loose joints, flat feet and poor dental formation, and in severe cases, they may develop a curved spine or bowed limbs. A bluish tint on the whites of the eyes is another common symptom. Parents have a 50 percent chance of passing on osteogenesis imperfecta, which manifests at birth.
Osteoporosis is a disease caused by low bone density, according to Medical News Today. Bone tissue normally undergoes a constant cycle of breakdown and replacement, but bones that are unable to restore tissue at a sufficient rate become too weak and structurally unstable. Osteoporosis makes the bones vulnerable to fracturing under minor stress, such as coughing or sneezing and falls that normally would not cause serious injury. Women, seniors and people with small bone structure have a higher risk of developing osteoporosis.
Paget's disease is caused by an abnormal cycle of tissue breakdown and regrowth, resulting in areas of weakened, oversized bones with new blood vessels, MedlinePlus states. Abnormal bone growth is most common in the limbs, collarbone, skull or spine. Many cases are asymptomatic, but possible symptoms include bone or joint paint, bowed legs, an enlarged head, reduced height, or skull deformities. Some people may experience headaches, hearing loss or fractures.