What is alopecia areata? Alopecia areata is a disease that causes hair loss. In alopecia areata, the immune system attacks the structures in skin that form hair (hair follicles). Alopecia areata usually affects the head and face, though hair can be lost from any part of the body. Hair typically falls out in small, round patches about the size of a quarter. In some cases, hair loss is more extensive.
What is Paget’s disease? Paget’s disease of bone is a chronic (long-lasting) disorder that causes bones to grow larger and become weaker than normal. Usually only one or a few bones have the disease. Many people with Paget’s disease do not have symptoms. However, the bone changes can cause: Bone pain. Misshapen bones. Broken bones (fractures). Problems in the joints near the bones with the disease. With treatment, many people can: Manage their symptoms. Improve pain. Control the effects of the disease.
What is reactive arthritis? Reactive arthritis happens when an infection causes joint pain and swelling. A bacterial infection in the digestive or urinary tract or the genitals usually triggers the condition, but arthritis symptoms typically do not start until a few weeks after you have recovered from the infection. The most common features of reactive arthritis are inflammation of the joints (especially the knees and ankles), eyes, and urinary tract, but not everyone gets all three, or they might not happen at the same time.
What is Sjögren’s syndrome? Sjögren’s syndrome is a chronic (long-lasting) disorder that happens when the immune system attacks the glands that make moisture in the eyes, mouth, and other parts of the body. The main symptoms are dry eyes and mouth, but the disorder may affect other parts of the body. Many people with Sjogren’s syndrome say they feel tired often (fatigue). They also may have joint and muscle pain. In addition, the disease can damage the lungs, kidneys, and nervous system.
What is osteogenesis imperfecta? Osteogenesis imperfecta (OI) is a disease that causes your bones to break (fracture) easily. OI is also called brittle bone disease. Your symptoms may be mild or severe, depending on the type of OI you have.
What is fibrous dysplasia? Fibrous dysplasia happens when abnormal fibrous (scar-like) tissue replaces healthy bone. The fibrous tissue weakens the bone over time, which can lead to: Broken bones. Bones that are misshapen (bowed or crooked). The disease can affect any bone in the body. Some people have no symptoms or only a few symptoms. Other people may have more symptoms. Although there is no cure for fibrous dysplasia, treatments may help to lessen pain, and physical therapy may help strengthen muscle and improve movement.
What are polymyalgia rheumatica and giant cell arteritis? Polymyalgia rheumatica and giant cell arteritis are closely linked inflammatory disorders. Some people have one of the disorders while others develop both of them. Polymyalgia rheumatica causes muscle pain and stiffness in the shoulders, upper arms, hip area, and sometimes the neck. Giant cell arteritis causes inflammation of arteries, especially those on each side of the head, scalp, and the aorta (the large artery that carries blood from the heart) and its main branches. The main symptoms of this disorder are: Headaches. Scalp tenderness. Jaw pain. Problems with your eyes, which may