Arthritis is an umbrella term for a group of more than 100 inflammatory conditions that affect the joints. Osteoarthritis and rheumatoid arthritis are the most common types, but there are many other forms. Diagnosing arthritis can involve blood tests, X-rays, and magnetic resonance imaging (MRI), along with tests to rule out other possible causes of your symptoms. Treatment is different depending on the cause, but the goal is always to relieve pain and inflammation while maintaining function.
In autoimmune disease, the immune system mistakenly identifies healthy tissues or substances in your body as dangerous infectious agents like viruses or bacteria. It then creates antibodies that attack and attempt to destroy that tissue or substance, leading to damage, inflammation, and pain. More than 100 autoimmune diseases have been identified.
Cartilage is a flexible but tough tissue that’s found in your joints, ears, nose, and airways. In joints, cartilage is basically a cushion and shock absorber, providing a smooth, low-friction surface for bones to glide over when you move. When it’s worn away or damaged, such as in arthritis, the result is pain, stiffness, and limited range of motion in the joint.
Also called the synovial lining or synovium, this is a thin connective tissue that contains synovial fluid. The synovium is inside your joints, providing padding between bones, muscles, and connective tissues. As you move, this membrane can change its shape and be compressed without being damaged. This is essential for proper movement of your joints.
Also called urate crystals, these are spiky crystalline structures that form inside joints when uric acid levels become abnormally high, as they do in gout. Uric acid crystals lead to considerable pain and often extreme inflammation. In later stages of gout, they may form clusters called tophi.
Arthritis has four main causes.
Rheumatoid arthritis is a chronic, inflammatory, autoimmune disease in which the immune system misfires and tries to destroy the lining of your joints (the synovium). In some cases, it has systemic effects and may target the eyes, heart, lungs, or other tissues. RA is a progressive disease that can lead to pain, loss of mobility, and joint deformity.
Psoriatic arthritis is a chronic, inflammatory, immune-mediated disease involving joint pain and skin lesions. A misfiring immune system damages skin cells called keratinocytes and the resulting inflammation can spread to the joints, nails, eyes, brain, and kidneys. Sausage-like swelling in the fingers and toes, nail deformity, and persistent fatigue are also common symptoms.
While symptoms vary from one type to another, most forms of arthritis share a group of symptoms, especially in the early stages. These include:
You may be able to lower your risk of developing some types of arthritis through lifestyle modifications, such as:
If your doctor suspects arthritis, they’ll likely examine your painful joints; order blood tests to check for inflammation, autoimmunity, or other potential markers; and send you for imaging studies, such as X-rays or magnetic resonance imaging (MRI), that can reveal damage to your joints and bones. They may also take steps to rule out other potential causes of your symptoms.
No, you can not give yourself arthritis by cracking your knuckles, no matter what your mother may have told you. The cracking sound you hear is just dissolved gasses quickly being released from the capsule that cushions your joint. That release is necessary for the capsule to expand properly when under pressure. Even so, too much cracking can damage the connective tissues surrounding the joint.
MedlinePlus. Gout. Bethesda (MD): National Library of Medicine (US).