Arthritis is a condition marked by inflammation and pain in the joints—areas where two bones meet. While there are over 100 types of arthritis, the most common causes include joint wear and tear, autoimmune responses, uric acid build-up, and infections. Each type of arthritis may be triggered differently, but understanding the root causes can help with prevention and management.

1. Wear and Tear

The most common form of arthritis, osteoarthritis (OA), develops when cartilage in the joints gradually wears down. While natural aging plays a role, excessive wear and tear accelerates joint damage.

Factors that contribute to OA include:

  • Abnormal joint structure that causes uneven wear

  • Obesity, increasing pressure and stress on joints

  • Previous joint surgery that alters joint mechanics

  • Traumatic injury, such as sports or work-related accidents

2. Autoimmune Response

Certain types of arthritis are caused by the immune system attacking healthy tissue. This leads to chronic inflammation and joint damage. These include:

  • Rheumatoid arthritis (RA)

  • Ankylosing spondylitis (AS)

  • Psoriatic arthritis (PsA)

Juvenile idiopathic arthritis (JIA), which affects children, is also believed to be autoimmune in nature.

3. Uric Acid Build-Up

Gout is caused by urate crystals accumulating in the joints, most often in the big toe. These sharp crystals are formed when the body breaks down purines, a compound found in:

  • Red meat

  • Seafood

  • Alcohol

  • Sugary drinks

A build-up of uric acid from purine metabolism triggers inflammation and painful flare-ups.

4. Infections

Some types of arthritis, like reactive arthritis and septic arthritis, can occur after infections. Infections that may lead to arthritis include:

  • Gonorrhea

  • Lyme disease

  • Respiratory infections

  • Staph infections

  • Tonsillitis

Reactive arthritis occurs as a response to infection elsewhere in the body. Septic arthritis, however, involves a direct joint infection, often from bacteria or fungi entering the bloodstream. People with weakened immune systems or recent joint surgeries are at higher risk.

Is Arthritis Passed Through Families?

Some forms of arthritis are hereditary, influenced by genetic makeup:

  • Ankylosing spondylitis (AS): Strongly associated with the HLA-B27 gene

  • Osteoarthritis (OA): Over 100 genetic variations are linked to OA risk

  • Rheumatoid arthritis (RA): Up to 60% of RA cases have a genetic basis, primarily through HLA class II genes

Chromosome 5q31 may also contain genes involved in AS, PsA, and RA development.

Who Gets Arthritis?

Certain groups are more likely to develop arthritis due to various risk factors:

  • Age: Risk increases with age, especially after 70

  • Economic status: Limited healthcare access may contribute to higher RA rates

  • Education: Low awareness about preventive care can delay diagnosis

  • Ethnicity: RA is more common in people of European or Native American descent

  • Military service: Physical stress and injuries raise arthritis risk; 1 in 3 veterans have arthritis

  • Sex: Gout is more common in men; OA and RA are more common in women

What Are the Risk Factors?

Some risk factors can be changed or avoided to reduce your arthritis risk.

infections
Infections may trigger autoimmune responses, particularly in RA and AS. Bacteria or viruses can resemble healthy cells, confusing the immune system and leading to joint inflammation.

diet
Low levels of omega-3 fatty acids increase RA risk. Regular consumption of fatty fish may reduce it.
In contrast, seafood rich in purines can trigger gout. Avoid anchovies, sardines, scallops, and mussels during flares.
Foods that may increase arthritis risk include:

  • Alcohol

  • Processed meats

  • Refined grains

  • Red meat

  • Sugary or salty foods

lifestyle habits
Certain habits can raise inflammation or weaken immunity, such as:

  • Smoking

  • Obesity

  • Chronic stress

  • Lack of sleep

joint injury
Physical trauma, especially repeated or job-related injuries, can damage cartilage and lead to osteoarthritis. ACL injuries, in particular, are linked to future OA risk.

A Quick Review

Arthritis is influenced by both genetic and environmental factors. Common causes include wear and tear, autoimmune reactions, infections, and uric acid accumulation. While you can’t always prevent arthritis, you can reduce your risk by:

  • Eating an anti-inflammatory diet

  • Maintaining a healthy weight

  • Avoiding smoking and excessive alcohol

  • Managing stress and sleeping well

  • Protecting joints from injury

Early recognition and lifestyle changes can help protect your joints and maintain long-term mobility.