The most common chronic condition of the joints in both the United States and Canada, osteoarthritis affects roughly 30 million people in just those two countries alone.

While osteoarthritis, or OA, can affect people of all ages, it's most common in men and women over the age of 65. Understanding osteoarthritis and how to prevent and manage the disease can help men and women over the age of 50 reduce their risk and live more comfortably even if they develop OA.

What is osteoarthritis?

According to the Arthritis Foundation, healthy joints are covered by cartilage, a flexible connective tissue that covers the end of each bone. Cartilage facilitates motion of the joints and serves as a cushion between the bones. When a person has OA, cartilage breaks down, causing swelling and pain and affecting the mobility of the joint. Over time, OA can worsen and cause bones to break down and develop bone spurs, which form when bones meet each other in the joints. OA can even advance to a point where cartilage wears away and bone rubs against bone, creating even more pain while damaging the joints even further.

What causes osteoarthritis?

Once considered a byproduct of the wear and tear the human body naturally endures over a lifetime, OA is now viewed as a disease, notes the AF. The following are some potential causes of OA.

· Genes: The AF notes that certain genetic traits can increase a person's likelihood of developing OA. Collagen is a protein that makes up cartilage, and, while rare, a genetic defect that affects the body's production of cartilage can lead to OA occurring in people as young as 20 years old. Researchers have also noted that the gene FAAH is more commonly found in people with OA of the knee than in people who don't have the disease. FAAH has been previously linked with pain sensitivity.

· Weight: Being overweight increases a person's risk for a host of ailments and diseases, and OA can be counted among them. Extra weight puts additional pressure on hips and joints, and over time those extra pounds can cause cartilage to break down more quickly than it would if the body was not carrying extra weight.

· Injury: Men and women who have suffered injuries to their joints may be at greater risk of developing OA than those with no such injury history.

· Overuse: Overuse of joints, tendons and ligaments can accelerate the breakdown of cartilage and increase a person's risk of developing OA. Cartilage also can break down more quickly in the bodies of athletes and people whose careers require them to stand for extended periods of time, bend over frequently and/or lift heavy items.

· Preexisting conditions: Conditions such as rheumatoid arthritis, hemochromatosis and acromegaly may also contribute to the development of OA among people diagnosed with such disorders.

Prevention and management of OA

Men and women who maintain healthy weights and exercise regularly and appropriately may be able to prevent the onset of OA. Appropriate exercises include strength training that focuses on building muscles around the joints, even if those joints are already affected by OA. Strong muscles around the joints can reduce the pain associated with OA, while range-of-motion exercises can improve flexibility of the joints and reduce stiffness. Aerobic exercise also helps men and women maintain healthy weights while facilitating weight loss for those who are already overweight.

Those already diagnosed with OA should speak with their physicians before beginning an exercise regimen, and such conversations can also include discussions about the various medications that can be used to reduce symptoms of OA.