What causes JIA?

It is important to remember that JIA is not contagious. It is also not known for certain what the exact cause is. In JIA, the immune system is not working normally. The immune system’s job is to fight off germs and disease. However, in JIA, the immune system attacks healthy joints, causing inflammation.

Joint inflammation in JIA

If the inflammation of JIA is not treated, it can lead to permanent damage of your joint. Damage occurs because the inflammation attacks the cartilage and bone. This can cause loss of cartilage, which leads to narrowing of the space between the bones. This in turn causes a loss of the protective cushioning that the cartilage provides, which can result in pain, stiffness and difficulty moving the joint.

Inflammation can “eat into” bones, causing damaged areas, or erosions, where the bone wears out. We can see erosions on X-rays or MRI tests​. Once this type of joint damage occurs, it usually cannot be reversed with medications.

See if you can find the erosions on the X-rays below.

Bone erosions

Arthritis inflammation can cause erosion in bones. When cartilage is damaged, the space between the bones in the joint narrows resulting in poor cushioning and in some cases, inability to move the bones properly.

Signs of JIA

Look at one of your own joints. Can you see or feel any of the following five signs of inflammation?

• Redness
• Swelling
• Heat or warmth
• Pain or tenderness when squeezing or moving the joint
• Difficulty moving your joint (stiffness).

Flares and remissions

When your joint becomes inflamed, you may have one or all of the above symptoms. If your inflammation gets worse, it is called a flare, or flare-up. If the inflammation in your joints goes away (and you no longer have signs and symptoms of JIA), it is called a remission.

You may have day-to-day changes in symptoms but that does not mean you are having a flare-up of your JIA. For example, one morning you may find your joints stiff and sore. The next day you may have no morning stiffness or pain. A flare is when you have an increase in inflammation for a prolonged period of time, lasting longer than just a few days.


Welcome to the Taking Charge: Managing JIA Online Program! In this section you will learn what to expect in the program, how to get started and how to set goals to better manage JIA.

JIA stands for juvenile idiopathic arthritis. Find out what causes JIA, the different types of JIA and how it will affect you now and in the future.

Diagnosing JIA may be difficult as joint pain and swelling may be a part of many different illnesses. Diagnosis of JIA typically includes a physical exam, blood tests and imaging studies.

Pain, stiffness, and tiredness or fatigue, are common symptoms of JIA. These symptoms can lead to difficulties with participating in school and sports activities, and enjoying time with your friends. Learn about pain, fatigue, and stiffness, how to manage symptoms and how these symptoms can cause stress.

There are several strategies you can use to help you cope with pain, stress, and sleep problems. These include relaxation, distraction, and managing your thoughts. In this section, learn more about how each of these strategies work.

When you know about your medications, you can talk to your doctor about them and make good choices for yourself. Find out about the different types of JIA medications, how they work, common side effects, and the importance of talking to your doctor about your medication plan.

Did you know that there are many other therapies that you can use to manage JIA symptoms? They can help to prevent complications so that you can do all the things you want to do. In this section, learn more about physical, occupational, and psychological therapies; maintaining healthy nutrition; surgical options for JIA, and more.

Your role in making decisions about your treatment plan is very important. Your health-care team and other members of your support system are available to help you make these decisions. In turn, they can help you to manage your JIA.

Whether you have JIA or not, you need to maintain a healthy lifestyle. Find out how to stay healthy and active, learn about puberty and relationships, healthy body image, and making healthy lifestyle choices.

Sometime between the ages of 18 to 22, you most likely will transition from your pediatric rheumatologist to the adult health care setting. At that time, there are a number of things you, your family, and your health-care team can do to help make this change go smoothly.