How does arthritis happen?

While there are many different types of arthritis, the two major categories are osteoarthritis (OA) and rheumatoid arthritis (RA). Each of these arthritis types have different causes.

Wear and tear
OA is most commonly the result of wear-and-tear to the joints. Use of the joints over time can contribute to the breakdown of protective cartilage in your joints. This causes bone to rub against bone. That feeling can be very painful and restrict movement.

Inflammatory
RA is when the body’s immune system attacks itself. Specifically the body attacks the membrane that surrounds the joint parts. This can result in inflamed or swollen joints, destruction of cartilage and bone, and ultimately pain. You may also experience other symptoms of inflammation, such as fever and loss of appetite.

Infection
Sometimes, traumatic injury or an infection in the joints can advance the progression of arthritis. For example, reactive arthritis is a type of arthritis that can follow some infections. This includes sexually transmitted infections such as chlamydia, fungal infections, and food-borne illnesses.

Metabolic
When the body breaks down purines, a substance found in cells and foods, it forms uric acid. Some people have high levels of uric acid. When the body can’t get rid of it, the acid builds up and forms needle-like crystals in the joints. This causes extreme and sudden joint point, or a gout attack. Gout comes and goes, but if left untreated it can become chronic.

Other causes
Other skin and organ conditions can also cause arthritis. These include:

psoriasis, a skin disease caused by excessive skin cell turnover
Sjogren’s, a disorder that can cause decreased saliva and tears, and systemic disease
inflammatory bowel disease, or conditions that include inflammation of the digestive tract such as Crohn’s disease or ulcerative colitis

Sometimes arthritis can occur with no known cause. But there are also factors that can increase your risk for all types of arthritis.

Age: Advanced age increases a person’s risk for arthritis types such as gout, rheumatoid arthritis, and osteoarthritis.

Family history: You are more likely to have arthritis if your parent or sibling has an arthritis type.

Gender: Women are more likely to have RA than men while men are more likely to have gout.

Obesity: Excess weight can increase a person’s risk for OA because it puts more pressure on the joints.

History of previous injuries: Those who have injured a joint from playing sports, from a car accident, or other occurrences are more likely to experience arthritis later.