What is psoriatic arthritis? Psoriatic arthritis can occur in people who have psoriasis (scaly red and white skin patches). It affects the joints and areas where tissues attach to bone. The joints most often affected are: The outer joints of the fingers or toes. Wrists. Knees. Ankles. Lower back.

What is hidradenitis suppurativa? Hidradenitis suppurativa is a skin disease that causes pimple-like bumps or boils on and under the skin. The disease is chronic (long lasting) and can be painful. HS does not spread from one person to another. HS starts in the hair follicle in the skin and happens where areas of skin may touch or rub together. Poor personal hygiene habits, such as not bathing or shampooing your hair, do not cause HS. In most cases, the cause of the disease is unknown.

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.

What is scleroderma? Scleroderma is an autoimmune connective tissue and rheumatic disease that causes inflammation in the skin and other areas of the body. This inflammation leads to patches of tight, hard skin. Scleroderma involves many systems in your body. A connective tissue disease is one that affects tissues such as skin, tendons, and cartilage. There are two major types of scleroderma: Localized scleroderma only affects the skin and the structures directly under the skin. Systemic scleroderma, also called systemic sclerosis, affects many systems in the body. This is the more serious type of scleroderma and can damage your blood

What is rheumatoid arthritis? Rheumatoid arthritis (RA) is a chronic (long-lasting) disease that mostly affects joints, such as the wrist, hands, feet, spine, knees, and jaw. In joints, RA causes inflammation that leads to: Pain. Swelling Stiffness. Loss of function. Rheumatoid arthritis is an autoimmune disorder because the immune system attacks the healthy joint tissues. Normally, the immune system helps protect the body from infection and disease. RA may cause you to feel unusually tired, to have occasional fevers, and to have a loss of appetite. It also may cause other medical problems in the heart, lungs, blood, nerves, eyes

What is arthritis? "Arthritis" literally means joint inflammation. Although joint inflammation is a symptom or sign rather than a specific diagnosis, the term arthritis is often used to refer to any disorder that affects the joints. Joints are places where two bones meet, such as your elbow or knee. There are different types of arthritis. In some diseases in which arthritis occurs, other organs, such as your eyes, heart, or skin, can also be affected. Fortunately, current treatments allow most people with arthritis to lead active and productive lives.

What is osteonecrosis? Osteonecrosis is a bone disease. It results from the loss of blood supply to the bone. Without blood, the bone tissue dies. This causes the bone to collapse. It may also cause the joints that surround the bone to collapse. If you have osteonecrosis, you may have pain or be limited in your physical activity. Osteonecrosis can develop in any bone, most often in the: Thigh bone (femur). Upper arm bone (humerus). Knees. Shoulders. Ankles. It is also called: Avascular necrosis. Aseptic necrosis. Ischemic necrosis.

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 acne? Acne is a common skin condition that happens when hair follicles under the skin become clogged. Oil and dead skin cells plug the pores, and outbreaks of lesions (often called pimples or zits) can happen. Most often, the outbreaks occur on the face but can also appear on the back, chest, and shoulders. For most people, acne tends to go away by the time they reach their thirties, but some people in their forties and fifties continue to have this skin problem.

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 knee problems? Knee problems happen when you injure or develop disease in your knee and it can’t do its job. The knees provide stable support for the body. They also allow your legs to bend and straighten. Both flexibility and stability are needed to stand, walk, run, crouch, jump, and turn. Other parts of your body help the knees do their job. These are: Bones. Cartilage. Muscles. Ligaments. Tendons.

What are sports injuries in youth? Although sports injuries can range from scrapes and bruises to serious brain and spinal cord injuries, most fall somewhere between the two extremes. Here are some of the more common types of injuries: Muscle sprains and strains. Injuries of a growth plate, area of tissue at the end of the long bones in growing children and teens. Injuries from overuse of muscles and tendons. Learn more about sports injuries.