Paget's disease of bone is a chronic skeletal disorder which may result in enlarged or deformed bones in one or more regions of the skeleton. Excessive bone breakdown and formation can result in bone which is dense but fragile. Pain is the most common symptom. Complications may include fractures, bowing of limbs and hearing loss if Paget's disease affects the skull. Though the cause or causes are not known, medical therapies are available to manage the disease.