Arthritis
In this condition factsheet:
The Facts on Arthritis
Arthritis is a chronic disorder that affects 1 in every 5 Canadians, or about 6 million people over the age of 15. And over half of those Canadians suffering with arthritis are younger than 65. It is one of the major reasons people see their doctor and one of the leading causes of disability in Canada.
The word arthritis is derived from the Greek words arthron for "joint" and itis for "inflammation". Today, the term is used for hundreds of different varieties of joint problems that have specific symptoms, such as pain, swelling, and stiffness.
Osteoarthritis (OA) and rheumatoid arthritis (RA) are the two most common types of arthritis conditions. Other types of arthritis include gout, ankylosing spondylitis, systemic lupus erythematosus (SLE or lupus), and psoriatic arthritis.
The effects of arthritis are often mild, but in some cases they can be crippling. RA affects about 1 out of every 100 people, affecting women more often than men. Joints and other organs may be affected by this form of arthritis. OA is estimated to affect about 14% of Canadians, also disproportionately affecting more women than men. OA can occur at any age but is more common as people age. It is also much more common in people who have an unhealthy body weight.
Causes of Arthritis
Some types of arthritis are genetic or inherited (i.e., they tend to run in families). Others are related to a chemical imbalance or are due to an overactive immune system. All forms of arthritis affect the joints to some degree, but others may have their most serious effects on other parts of the body.
OA is the most common form of arthritis, primarily affecting people over the age of 60 years, or in younger people who have had serious joint injuries. It is degenerative in nature – cartilage in the joints gradually wears away, causing the ends of the bones to rub against each other.
OA can develop spontaneously for no apparent reason or be due to a secondary cause, where the joint damage results from an injury or trauma. By far the greatest risk factor for OA of the hips and joints of the legs is being overweight.
Wear-and-tear is the principal sign of OA, but science has begun to unravel the specific mechanisms of the disease. Inflammation does not play as great a role as in other types of arthritis, but for some people it can be a prominent feature. An athlete who has suffered joint injuries or someone who works in a job that puts daily stress on the joints is at higher risk of developing OA later in life.
RA is caused by inflammation and thickening of the joint's lining, called the synovium. There is an identified genetic predisposition for RA, and scientists suspect that inflammatory forms of arthritis such as RA may be caused by the body's immune system being "triggered" by a bacterial or viral infection, however this theory is unconfirmed. The result is an abnormal immune response that destroys the body's own tissues. In the case of RA, the joints are the primary target.
Some forms of arthritis are due to metabolic problems, called crystal-associated arthritis. These include gout and pseudogout, which are caused by crystal deposits within the joints. Men are about 3 to 4 times as likely to have gout compared to women, and women become more prone to developing gout after menopause compared to pre-menopausal women. People over the age of 65 are more commonly affected.
Gout may be genetic, but it can also be precipitated by excessive alcohol consumption, dehydration, obesity, protein-rich diets, trauma, high blood pressure and certain medications. Gout results from the accumulation of uric acid, a waste product from the breakdown of digested proteins. Excess uric acid forms sodium urate crystals that collect in many tissues, including the joint linings, which causes inflammation. It can also lead to kidney stones.
Symptoms and Complications of Arthritis
Symptoms of OA include:
- stiffness (lasting <30 minutes) on awakening or after prolonged rest
- pain in a joint during or after use
- discomfort in a joint before or during a change in weather
- swelling and a loss of flexibility in a joint
- bony lumps (called Heberden and Bouchard nodes) that develop on the end or middle joint of the fingers
- grinding sensation or creaking sound when the joint moves
Symptoms of RA include:
- pain and swelling in any joint, but usually symmetrically (if one joint is affected, the other side will soon follow)
- overall aching or stiffness, especially after sleeping or periods of motionlessness
- joints that are swollen, red, and warm to the touch
- nodules, or lumps, that most commonly occur near the elbow (but can occur anywhere)
- fatigue and weakness
- mild fever
- weight loss or poor appetite
Symptoms of gout include:
- The sudden appearance of joint inflammation with severe pain, swelling, heat, and redness. It can often be difficult to differentiate it from an acute infection. Any joint can be affected, but the big toe is by far the most common. The attack may last up to a week or more without treatment, then usually resolves and gets better on its own.
- Flank or groin pain and blood in the urine (visible or only on testing) may signal a kidney stone.
