What causes arthritis?

Arthritis is defined as inflammation of the joints, which can manifest itself in approximately 100 different types of arthritis.

It can also affect your eyes, heart or skin. Current treatments  available for people with arthritis allow them to have productive and active lives.

Researchers are investigating various factors that contribute to arthritis, including genetics, lifestyle and the environment. Rheumatoid (RA) and osteoarthritis are two of the most common types of arthritis, and they damage joints in different ways.

RA is an autoimmune or inflammatory disease. It occurs when the body’s immune system attacks the synovial membrane that lines all the joint parts. As the lining becomes inflamed and swollen, the disease destroys the cartilage and bone.

Osteoarthritis is damage to the joint’s cartilage, which is the hard, slick coating on bones between the joints, allowing joint motion without friction. When the cartilage is damaged or worn away, the bone grinds on bone directly, causing pain and a reduced range of motion. Over time, it can occur from wear and tear or happen more quickly from infection or joint injury. Osteoarthritis is a common cause of knee arthritis.

RA and juvenile arthritis have been associated with specific genes and environmental factors that may trigger the condition. Some people are born with certain versions of genes called human leukocyte antigen (HLA) that may predispose them to develop RA or other autoimmune conditions. Infections in the joints can also cause arthritis, and excess uric acid buildup in a joint can lead to gout, a type of arthritis.

Several factors can increase your risk for arthritis or make your arthritis worse. Some risk factors you may be able to control, while others you cannot control. Some factors include being overweight or obese, infections such as bacteria or viruses affecting the joints, joint injuries or repetitive stress, occupations with active knee-bending or squatting, and smoking. Other factors may include age, gender and genetics.

Evidence suggests that knuckle cracking does not cause arthritis. Additional evidence may suggest that the popping sound heard when someone cracks their knuckles is caused by bubbles bursting in the fluid that helps to lubricate the joints. It’s important to note that it is not recommended to force your joints to crack. 

However, it can be concerning if you have cracking, popping, snapping or creaking of a joint accompanied by pain. This can occur from an injury, such as a cartilage tear from a torn meniscus or cartilage degeneration from wear and tear over time due to osteoarthritis. Talk to your healthcare provider if you experience pain or other symptoms when your joints crack.

If you have signs of arthritis, see your healthcare provider. Having arthritis diagnosed early and treating it aggressively can help prevent visible joint changes, chronic pain, loss of mobility and decreased function.

Clinically reviewed and updated by Nora Laberee, May 2022.