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 Raynaud’s phenomenon? Raynaud’s phenomenon is a condition that causes the blood vessels in the hands and feet to narrow, decreasing blood flow. When this happens, parts of the body—usually the fingers and toes—become cold and numb, and change color (usually, to white or blue). An attack usually happens from exposure to cold or stress.

What is ichthyosis? Ichthyosis is a group of skin disorders. It leads to dry, itchy skin that appears scaly, rough, and red. The symptoms can range from mild to severe. Ichthyosis can affect only the skin, but sometimes the disease can affect internal organs, too.

What are autoinflammatory diseases? Autoinflammatory diseases refer to problems with the immune system, which usually fights off viruses, bacteria, and infection. The problem causes your immune cells to attack your body by mistake. This can cause swelling that produces fever, rash, joint swelling, or serious buildup of a blood protein in your organs.

What are sports injuries? The term “sports injury” refers to the kinds of injuries that most commonly happen during sports or exercise, such as sprains, strains, and stress fractures This health topic focuses on types of sports injuries that affect muscles, tendons, ligaments, and bones. There are several different types of sport injuries. The symptoms you have and your treatment depends on the type of injury. Most people recover and return to normal activities.

What is scoliosis? Scoliosis is a sideways curve of the spine. Children and teens with scoliosis have an abnormal S-shaped or C-shaped curve of the spine. The curve can happen on either side of the spine and in different places in the spine. With treatment, observation, and follow-up with the doctor, most children and teens with scoliosis have normal, active lives.