What Is the Main Cause of Arthritis?

Reviewed on 5/5/2022
Senior woman with arthritis sitting on a bed and massaging knee
There is no single main cause for arthritis, and causes depend on the type of arthritis. Causes and risk factors include age, sex, genetics, weight, sports activity, genetics, and more.

Arthritis describes over 100 different conditions that involve inflammation of any part of a joint, including the joint lining (synovium), cartilage, bones, and supporting tissues. Arthritis may affect one, a few, or many joints throughout the body.

The three most common types of arthritis include:

  • Osteoarthritis
    • The most common type of arthritis that often develops with age
    • A chronic condition in which the cartilage between bones that cushions the joints wears down and as it does, the bones rub against each other causing pain, stiffness, swelling, and reduced joint motion
  • Rheumatoid arthritis (RA)
    • A chronic autoimmune disorder characterized by persistent joint pain, swelling, and stiffness
    • Differs from some other forms of arthritis because it affects both sides of the body
  • Psoriatic arthritis
    • A type of inflammatory arthritis that may develop in people with psoriasis, a chronic autoimmune skin condition that causes fast skin cell growth and renewal

Other types of arthritis include: 

There is no single main cause for arthritis, and causes depend on the type of arthritis. 

Causes and risk factors for osteoarthritis include:

  • Advancing age 
    • At least 80% of people over age 55 have some X-ray evidence of osteoarthritis
  • Gender 
    • Women are two to three times more likely than men to develop osteoarthritis 
  • Obesity
  • Occupations that require frequent squatting and kneeling
  • Joint injury or trauma
  • Sports 
    • Wrestling, boxing, pitching in baseball, cycling, gymnastics, soccer, and football

The cause of rheumatoid arthritis is unknown but it is believed certain factors may affect a person's risk of developing the condition, such as:

  • Age 
    • Middle-aged or older
  • Female sex 
    • Twice as likely as men to develop RA
  • Genetics 
    • People with a relative who has RA have an increased risk 

Triggers for rheumatoid arthritis may include:

The cause of psoriatic arthritis is not known, but it is thought that genetic, immunologic, and environmental factors play a role. 

About forty percent of people with psoriatic arthritis have family members with psoriasis or psoriatic arthritis. 

What Are Symptoms of Arthritis?

The main symptom of most types of arthritis includes joint symptoms, such as: 

  • Pain
  • Tenderness
  • Swelling 
  • Stiffness
  • Redness
  • Warmth
  • Limited movement/decreased range of motion or flexibility

Depending on the type of arthritis, other symptoms that can accompany joint symptoms include: 

How Is Arthritis Diagnosed?

Arthritis is diagnosed with a medical history and physical examination, along with laboratory and imaging tests.

Tests used to diagnose arthritis include: 

  • Blood tests
    • Rheumatoid factor (RF) 
    • Antinuclear antibody (ANA) for SLE
    • Anti-cyclic citrullinated peptide (CCP) 
  • Arthrocentesis (also called joint aspiration or joint tap)
  • X-rays (also used to monitor changes in the joint over time)
  • Computed tomography (CT) scan
  • Magnetic resonance imaging (MRI)
  • Ultrasound

What Is the Treatment for Arthritis?

Treatments for arthritis include:

Reviewed on 5/5/2022
Image Source: iStock Images