RENEE MONTAGNE, host:
The graying of America means that more people than ever before have osteoarthritis. According to the National Institutes of Health, the condition now affects 27 million Americans.
NPR's Brenda Wilson reports, however, that the joint pain of osteoarthritis isn't necessarily inevitable.
BRENDA WILSON: A lot of things cause joint pain at any age. An injury, of course, overuse or exertion, can make you sore and infection. But Dr. Robert Bunning, an internist and rheumatologist at The National Rehabilitation Hospital in Washington, D.C. says that his older patients are not surprised by the effects of aging under joints.
Dr. ROBERT BUNNING (Internist and Rheumatologist, The National Rehabilitation Hospital): For example, osteoarthritis under age 45, perhaps two percent of the population will have osteoarthritis. But over age 65, about two-thirds of the population would meet criteria for osteoarthritis. So the average person has osteoarthritis.
WILSON: As you edge past 60, the body loses some capacity to regenerate and repair tissue, including cartilage that cushions the ends of bones where they meet. The space between bones narrows. Over time, bones no longer fit comfortably into each other, and fluid from the lining of the joints seeps into bones. Bone rubs against bone, and the joint becomes inflamed.
Dr. BUNNING: The word arthritis means inflammation of the joint. And the signs of inflammation are pain, swelling, warmth, redness.
WILSON: Dr. Robert Bunning says the joints affected are usually the fingers, knees, hips, and spine. There are about 200 joints, as many joints as there are bones. They're not isolated units, but a dynamic interplay of ligaments, tendons, cartilage, joint fluid and membrane that hold the skeleton together and help us move.
Dr. David Hamerman, a geriatrician with the Albert Einstein College of Medicine, says any of them could be a source of joint pain.
Dr. DAVID HAMERMAN (Geriatrician, Albert Einstein College of Medicine): There are so many structures within the joint that become stressed or changed or even torn with aging.
WILSON: But Hamerman says the causes of osteoarthritis are known. They're genetic and environmental. And they often start in early life.
Dr. HAMERMAN: The major environmental factors being obesity, which contributes to knee osteoarthritis. Congenital deformities of the hip, which can distort the joint of the hip and predisposed to osteoarthritis or extreme trauma or stress on a joint, which might cause an injury. Osteoarthritis is more often found in persons who have injured joint structures.
WILSON: In fact, anything that has disturbed the natural alignment of the joints and how it functions, occupations with repeated stressful motions - such as bending and lifting - can also lead to osteoarthritis. Osteoarthritis isn't always painful, and pain isn't always osteoarthritis. But even when mild symptoms crop up, Dr. Bunning at The National Rehabilitation Hospital says something can be done about it.
Dr. BUNNING: If you're 80 years old and have a little bit of stiffness, you don't necessarily have to run off to the doctor. You can say, I probably have some mild stiffness related to mild osteoarthritis. I could take the usual treatment for that, which would be something like Tylenol or, you know, Advil or Aleve over-the-counter as long as you are cleared by your doctor to take those medications. It doesn't mean every patient who has a little bit of aching and stiffness needs an MRI.
WILSON: And he says exercises are effective at any age.
Dr. BUNNING: There's a lot of good evidence that strengthening the muscles around a painful knee, especially quadriceps strengthening, can be extremely helpful. Shoe inserts and even just proper shoes — tie shoes with a good cushion worn with a good sock — can help relieve pain.
WILSON: Bunning says, if pain persists, however, if a pain in the hip especially keeps you awake at night, if your ability to move about is affected, doctors sometimes use steroid injections into the joint and surgery is also possible.
Brenda Wilson, NPR News.