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 osteoarthritis? Osteoarthritis is a joint disease that happens when the tissues in the joint break down over time. It is the most common type of arthritis and is more common in older people. People with osteoarthritis usually have joint pain and, after rest, stiffness (inability to move easily) for a short period of time. The most commonly affected joints include the: Hands (ends of the fingers and at the base and ends of the thumbs). Knees. Hips. Neck. Lower back. Osteoarthritis affects each person differently. For some people, osteoarthritis does not affect day-to-day activities. For others, it causes
What is osteonecrosis? Your bones are made up of living cells that need a blood supply to stay healthy. In osteonecrosis, blood flow to part of a bone is reduced. This causes death of bone tissue, and the bone can eventually break down and the joint will collapse. Osteonecrosis can happen to any bone, but most often it develops in the ends of long bones, such as the: Thigh bone. Upper arm bone. Less often, the bones of the elbows, ankles, feet, wrists, and hands are affected. When the disease involves part of a bone in a joint, it can
What is Marfan syndrome? Marfan syndrome is a genetic disorder that affects the body’s ability to make healthy connective tissue, which supports the bones, muscles, organs, and tissues in your body. The condition can affect different areas of the body, including: Bones, ligaments, tendons, and cartilage. Organs, such as the heart and lungs. Skin.
What is psoriasis? Psoriasis is a chronic (long-lasting) disease in which the immune system works too much, causing patches of skin to become scaly and inflamed. Most often, psoriasis affects the: Scalp. Elbows. Knees. The symptoms of psoriasis can sometimes go through cycles, flaring for a few weeks or months followed by times when they subside (or go into remission). If you have psoriasis, you may have a higher risk of getting other serious conditions, including: Psoriatic arthritis. Heart attack or stroke. Mental health problems, such as low self-esteem, anxiety, and depression.