A few aches and pains are common after age 50 or so. But pain in the knees, particularly if it comes on more suddenly, can signal an injury or health condition that needs more attention. The following are some of the more common reasons behind knee pain. But don’t attempt to diagnose yourself at home; these tips are meant as a guide only. Schedule an appointment with your doctor for a proper diagnosis and treatment plan.

Osteoarthritis. As cartilage around the knee joint deteriorates over time, pain, stiffness, swelling, and loss of mobility can be the result. This condition can be the result of an old injury, but is sometimes just caused by “wear and tear” on joints after age 50.

Rheumatoid arthritis. If your immune system backfires and begins to attack your own body, the knees are a common spot for complaints. However, usually with this condition you will have problems with additional joints as well.

Weight. The more you weigh, the worse the stress on your knees. Each additional pound of body weight translate into five to seven pounds of additional stress upon your knees. If it seems that your knees are just more sore than usual, especially if you’ve gained some weight, a diet and exercise plan might be in order.

Tendonitis or bursitis. Inflammation of the tendons around the knee (tendinitis) can result from exercise-related injuries. This is particularly common in older people, because flexibility wanes as we age. Bursitis can be the result of inflammation in the bursae (the fluid-filled sacs around the kneecap). With both of these conditions, warmth, swelling, and tenderness might be present.

Meniscal tear. This type of injury can be the result of a twisting motion. This injury can occur suddenly, or over time through small tears that gradually get worse. Your symptoms will include pain, swelling difficulty squatting or standing, and possibly a clicking sound in the knee. You might also feel as though your knees occasionally “lock up”.

These are just some of the most common conditions and injuries that can affect the knees. If you suspect a problem, please visit your primary care physician immediately. Thoroughly describe all symptoms and remember to mention any new or old injuries that might have impacted your knees. If a type of arthritis is the culprit, your physician can get you started on a regimen of treatment so that you stay more comfortable.