Causes of Arthritis
Scientists do not yet know the specific causes of most types of arthritis. For the few types of arthritis whose specific causes are known, the causes can vary depending on the type of arthritis a person has. For example, hemorrhagic arthritis is caused by blood getting into the joint and causing inflammation, while gout is caused when the levels of uric acid become so high that crystals form inside the joint.
What Causes Arthritis?
The term arthritis is used to describe more than 100 rheumatic diseases and conditions that affect joints, the tissues which surround the joints, and other connective tissue. Despite a lot of research, scientists still know very little about these conditions. In fact, scientists have been able to figure out the specific causes of only a few types of arthritis. Therefore, in most cases, the answer to "What causes arthritis?" is not known.
However, in some cases, the causes of arthritis are known. For other types, scientists know risk factors but not the actual causes. Let's look at several different categories of arthritis as we discuss possible causes or risk factors. These categories can include:
- Noninflammatory (osteoarthritis being the most common)
- Inflammatory (including rheumatoid arthritis and gout)
- Infectious (including septic arthritis)
Noninflammatory Arthritis CausesThe most common type of noninflammatory arthritis is osteoarthritis (formerly known as degenerative joint disease). This is also the most common type of arthritis seen in older adults. In fact, many people use the terms arthritis and osteoarthritis interchangeably, since osteoarthritis is so common (similar to the way that people use "heart disease" to mean coronary artery disease).
Arthritis research scientists do not know the exact cause or causes of osteoarthritis. They do know a number of factors that increase a person's chances of developing the disease.
Some risk factors for osteoarthritis include:
- Getting older
- Being overweight
- Having weak muscles
- Certain medical conditions
- Joint injuries
- Repetitive stresses on the joints.
(Click Causes of Osteoarthritis for more information on these risk factors.)