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 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 Behçet’s disease? Behçet’s disease can affect different parts of your body. If you have the disease, you probably have sores in the mouth or on the genitals (sex organs). More serious symptoms can include swelling, heat, redness, and pain in the eyes and other parts of the body. The disease is named after the doctor who first described it, Dr. Hulusi Behçet.
What is giant cell arteritis? Giant cell arteritis causes the arteries of the scalp and neck to become red, hot, swollen, or painful. The arteries most affected are those in the temples on either side of the head. These arteries narrow, so not enough blood can pass through. It is important that you get treatment right away. Otherwise, the arteries could be permanently damaged. There is also a risk of blindness or stroke. If you have giant cell arteritis, your doctor should also look for signs of another disorder, polymyalgia rheumatica. These conditions often occur together.