Causes and Risk Factors of Arthritis

There are 100 different forms of arthritis, each with its own set of causes and risk factors. The most common types include osteoarthritis, rheumatoid arthritis, and gout. Determining the cause of arthritis can be difficult since multiple, overlapping factors typically contribute to its development. Possible causes of arthritis include age- and lifestyle-related wear and tear, infections, injuries, and autoimmune conditions.

Common Causes

With each of the major types of arthritis, there are different causes and risk factors, but these are the ones most often at play.

Older Age

Older age is a major factor in arthritis as cartilage becomes increasingly brittle over time and has less capacity to repair itself. The development of osteoarthritis is typically seen to begin between the ages of 40 and 50, although it can start earlier in other forms of the disorder.

Injury

Previous joint damage can cause irregularities in the normal, smooth joint surface. Prior injury certainly plays a part in the development of arthritis of the wrist, where the complex bone and cartilage structure can be easily compromised by impact or compression. Another example is arthritis caused by a tibial plateau fracture, where a broken area of bone enters the cartilage of the knee joint.

Infection

Certain infections around the joint, whether bacterial or viral, lead to the deterioration of cartilage or the formation of skin lesions that penetrate the joint and synovial membrane. People who experience a joint infection (septic joint), multiple episodes of gout, or recurrent staph infection around a joint run a higher risk of developing arthritis.

Autoimmune Factors

Rheumatoid arthritis, psoriatic arthritis, juvenile idiopathic arthritis, and lupus are among the types of inflammatory arthritis in which your immune system attacks your own tissues. What causes this to happen is unclear and may be due to several factors, including genetic predisposition, infections, or environmental exposures. Your immune system is sensitized and makes antibodies that attack your joints and organs.

Genetics

Genetics seem to play a key role the development of certain types of arthritis, although the association is still not fully understood. A family history can suggest an increased risk depending on the type of arthritis involved. For example, approximately 40% of patients with psoriasis or psoriatic arthritis have family members who have one of these conditions.

Certain forms of rheumatoid arthritis are linked to genetic markers known as HLA-B27 and HLA-DR4. Variants in other genes may also contribute, including:

• STAT4, a gene that plays an important role in the regulation and activation of the immune response
• TRAF1 and C5, two genes associated with chronic inflammation
• PTPN22, a gene associated with both the development and progression of rheumatoid arthritis

Gout, defined by a problem with the production and elimination of uric acid, is also influenced by genetics. Hereditary hyperuricemia, caused by SLC2A9 and SLC22A12 mutations, is one condition that impairs the excretion of uric acid by the kidneys.

How genetics can influence developing osteoarthritis is still being explored. A review found differences in heritability depending on which joint was affected. It was most influential for spinal arthritis (70%) and hip arthritis (60%), and less so for that of the knee (40%). Osteoarthritis seems to be influenced by several gene variants and having more of them at the same time adds to risk.

Lifestyle Risk Factors

There are things you do that can increase your risk of some forms of arthritis and might worsen the effects of other types. Importantly, the stress you place our joints today can lead to the development of arthritis later.

Obesity

Obesity is a factor as it directly contributes to the stress a joint can be placed under. This is especially true for hip and knee joints, where excessive weight have a direct impact and cause inflammation that gradually deteriorates joint tissues.

Occupational Hazards

Jobs and activities involving manual labor or repetitive motion can lead to joint damage and arthritis. As such, protective measures are often put in place to minimize damage caused by heavy lifting and activities that demand the constant flexion and extension of a joint. Even minor repetitive movements like pulling a lever or pushing a cart can cause deterioration of bone and joint cartilage over a period of years.

Sports

High-level sports activity can lead to arthritis if it involves blunt force impact or results in damage to a bone or joint. This happens in contact sports, but also those that place persistent impact stress on a joint, such as long-distance running.

On the flip side, moderate, routine exercise can minimize the symptoms or development of arthritis by bolstering the muscular structure around a joint, giving it support.

Smoking

Cigarette smoking increases your risk of developing rheumatoid arthritis. It can also worsen the condition and cause other medical problems.

Foods and Medications

In the case of gout, certain foods and medications can increase the level of uric acid, which can then cause a gout flare. You will often be given a list of what to avoid, including beer and foods high in purine.

A Word From Verywell

The development of arthritis is a complex and intertwined process with multiple factors at work. While you cannot control all of them, there are steps you can take to prevent arthritis or, if you've already been diagnosed, its progression. The more you are dedicated to this, the more likely it is that simple treatments, if needed, remain effective for as long as possible.