What Causes Arthritis?
Arthritis is not a single disease but rather an umbrella term for over 100 different types.
Here are some of the most common and notable types, though this list is by no means exhaustive:
- Osteoarthritis (OA): The most common form, it involves wear-and-tear damage to the joint's cartilage.
- Rheumatoid Arthritis (RA): An autoimmune disorder where the immune system attacks the joints.
- Juvenile Arthritis: Arthritis that affects children.
- Psoriatic Arthritis: Associated with the skin condition psoriasis.
- Ankylosing Spondylitis: Affects the spine, causing vertebrae to fuse.
- Gout: Caused by the crystallization of uric acid in a joint.
- Lupus: An autoimmune disease that affects joints and other parts of the body.
- Fibromyalgia: A disorder causing muscle pain and fatigue.
- Infectious Arthritis: Caused by an invading microorganism, such as bacteria or viruses.
- Reactive Arthritis: Arthritis that arises in response to an infection elsewhere in the body.
- Pseudogout (CPPD): Caused by calcium-containing crystals in the joints.
- Polymyalgia Rheumatica: Causes muscle pain and stiffness.
- Temporal Arteritis (Giant Cell Arteritis): Inflammation of blood vessels.
- Sjogren's Syndrome: Attacks the glands that produce tears and saliva.
- Still's Disease: A rare type of arthritis that can cause high fevers and a rash.
- Polymyositis: Causes muscle inflammation.
- Dermatomyositis: Affects the skin and muscles.
- Behcet's Disease: Causes inflammation of blood vessels.
- Systemic Sclerosis (Scleroderma): Causes skin to thicken and harden.
- Mixed Connective Tissue Disease (MCTD): Features of several connective tissue diseases.
- Bursitis: Inflammation of the bursae, small sacs of fluid that reduce friction between bones and other moving structures in the joints.
- Tendinitis: Inflammation of a tendon, the thick cords that attach bone to muscle.
- Septic Arthritis: Arthritis caused by a bacterial or fungal infection.
- Lyme Disease: Tick-borne illness that can lead to joint inflammation.
- Chondrocalcinosis: Calcium buildup in the joints.
- ... and many more.
Many of these conditions have subtypes. For instance, juvenile arthritis can be further classified into juvenile idiopathic arthritis (JIA), juvenile lupus, juvenile scleroderma, Kawasaki disease, mixed connective tissue disease, and fibromyalgia, among others.
The wide variety of arthritis types is due to the numerous potential causes (from infections to immune system malfunctions) and the many joints and tissues that can be affected.
The primary cause is the deterioration or inflammation of one or more joints. Factors leading to arthritis include:
- Genetics: Some types of arthritis run in families.
- Age: As you age, your joints tend to wear out.
- Injuries: Past injuries can lead to arthritis in the injured joint.
- Infections: Some microbial agents can infect joints and trigger arthritis.