What is reactive arthritis? Reactive arthritis is pain or swelling in a joint that is caused by an infection in your body. You may also have red, swollen eyes and a swollen urinary tract. These symptoms may occur alone, together, or not at all. Most people with reactive arthritis recover fully from the first flare of symptoms and can return to regular activities 2 to 6 months later. Some people will have long-term, mild arthritis. A few patients will have long-term, severe arthritis that is difficult to control with treatment and may cause joint damage.

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.

What are growth plate injuries? The growth plate is the area of tissue near the ends of long bones in children and teens that determines what length and shape the bone will be once it is done growing. Each long bone— the thigh bone, the bones in the forearm, and the bones in the hands and fingers—has at least two growth plates, one at each end. Once your child has finished growing, the growth plates close and are replaced by solid bone. The growth plates are weak areas of your child’s growing skeleton, making it easier to injure them. Injuries

What are shoulder problems? Most shoulder problems happen when soft tissues in the joint and shoulder region break down.

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 atopic dermatitis? Atopic dermatitis, often called eczema, is a chronic (long-lasting) disease that causes the skin to become inflamed and irritated, making it extremely itchy. Scratching leads to: Redness. Swelling. Cracking. “Weeping” clear fluid. Crusting. Scaling. In most cases, there are times when the disease is worse, called flares, followed by times when the skin improves or clears up entirely, called remissions. Atopic dermatitis is a common condition, and anyone can get the disease. However, it usually begins in childhood. Atopic dermatitis cannot be spread from person to person. No one knows what causes atopic dermatitis. Depending on

What is osteopetrosis? Osteopetrosis is a rare disorder that causes bones to grow abnormally and become too dense. When this happens, bones can break easily. In addition, bones may be misshapen and large, causing other problems in the body, such as problems with: Seeing and hearing. Fighting infection. Controlling bleeding. Osteopetrosis is a genetic disease that a child inherits from their parents. The disorder may be mild to severe, and symptoms may show up early after birth or later in adulthood.

What is pemphigus? Pemphigus is a type of disease where the body’s immune system attacks healthy cells in the top layer of skin (epidermis). It causes blisters on the skin and in the mouth, nose, throat, eyes, and genitals. Some forms of pemphigus can cause death if not treated.

What are sports injuries? Sports injuries are injuries that happen when playing sports or exercising. There are two kinds of sports injuries: Acute injuries occur suddenly when playing or exercising. For example: Sprained ankles. Strained backs. Broken bones. Chronic injuries happen after you play a sport or exercise for a long time.

What is back pain? Back pain is one of the most common medical problems in the United States. It might feel like a dull, constant ache or a sudden, sharp pain. Back pain can result from: An accident. A fall. Lifting something heavy. Changes that happen in the spine as you age. A disorder or medical condition. Treatment depends on the cause and symptoms of your pain. You can do things to improve your health and lower your chance of developing chronic (long-lasting) back pain.

What are sprains and strains? A sprain is an injury to a ligament (tissue that connects two or more bones at a joint). When a sprain happens, one or more ligaments is stretched or torn. A strain is an injury to a muscle or tendon (fibrous cords of tissue that connect muscle to bone). In a strain, a muscle or tendon is stretched or torn.

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 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 is osteoporosis? Osteoporosis is a disease that causes bones to become weak and brittle. This increases your risk of broken bones (fractures). Osteoporosis is a “silent” disease because you may not have symptoms. You may not even know you have the disease until you break a bone. Breaks can occur in any bone but happen most often in: Hip bones. Vertebrae in the spine. Wrist. You can take steps to help prevent osteoporosis and broken bones by: Doing weight-bearing exercises, such as walking or dancing, and lifting weights. Not drinking too much alcohol. Quitting smoking, or not starting if