A family history of the disease. Genetics accounts for more than 50 percent of all cases of osteoarthritis.

Inactivity. If joints aren’t used in a long time, the cartilage protecting the joints becomes weak and may eventually lose its function.

Age. As the body ages, cartilage becomes less flexible and loses its ability to regenerate. Also, the repeated wear and tear on these joints over the years can lead to osteoarthritis.

Traumatic injury to the joint. Former athletes and ballet dancers in particular are susceptible to developing the disease from repeated injuries to various joints.

Obesity. Extra weight puts more strain on the joints.

Lack of vitamin D. Low levels of vitamin D make bones more susceptible to osteoarthritis.

Steady or intermittent pain in a joint

Stiffness after getting out of bed

Joint swelling or tenderness

Crunching feeling or sound in the joint (called crepitus)

Enlarged, gnarled finger joints, which can be a sign of osteoarthritis in the hands

Limited joint movement.

Blood test. A blood test can rule out other causes of pain in your joints.

Joint aspiration. Your physician might need to test a sample of fluid from your joint. During a joint aspiration, a needle is inserted into the joint to collect fluid.

X-rays. X-rays can help detect cartilage loss, bone damage, and bone spurs.

Exercising on a regular basis to keep the joints moving

Managing your weight to reduce the stress on the joints

Increasing your vitamin D intake

Limiting your participation in high-risk sports such as football, tennis, rugby, and basketball.

Nonsteroidal anti-inflammatory drugs (NSAIDs). These medications include aspirin (Anacin, Bayer, Bufferin), ibuprofen (Advil, Motrin IB, Nuprin), ketoprofen (Orudis KT), and naproxen sodium (Aleve). NSAIDs, which can help relieve inflammation, joint pain, and swelling, are available by prescription or over the counter. NSAIDs block the body’s production of prostaglandins, chemicals that are released when the body is in pain. Prostaglandins can contribute to the pain, heat, and swelling that occur after tissue has been damaged. Using NSAIDs for a long time could lead to ulcers, bleeding, and damage to the stomach lining.

Acetaminophen (Tylenol and others). Acetaminophen may be as effective as NSAIDs in relieving pain. This medication is gentler on the stomach than aspirin and other NSAIDs, but it can cause liver damage in heavy drinkers. Using acetaminophen for a long time could cause kidney and liver damage.

Topical pain-relieving creams. Creams such as those that contain capsaicin can numb the skin temporarily.

Corticosteroids. Your physician may inject these powerful anti-inflammatory hormones into the affected joint to relieve pain, but they’re not recommended for long-term use.

Hyaluronic acid. This new medicine, used to treat osteoarthritis of the knee, is a normal component of the joint involved in lubrication and nutrition. Most patients feel relief from arthritic pain after 3 to 5 injections of hyaluronic acid.

Glucosamine and chondroitin sulfate. These components of cartilage are available as supplements that can help ease pain. Initial research showed that taking the supplements for a month relieved symptoms in some patients with arthritis.

Warm towels or hot packs, warm-water therapy, and cold therapy can help ease joint pain and increase mobility.

Supportive shoes with rubber soles will absorb shock and reduce further damage to your joints.

Special exercises can restore joint movement and strength. Work with your doctor to create an exercise program for your individual needs and abilities.

Weight-management programs help reduce the amount of stress you put on your joints.

Joint replacement (arthroplasty). After removing the ends of the damaged bones, a surgeon will replace them with artificial joints made of metal, ceramic, or plastic.

Bone repositioning (arthrodesis/fusion). During this procedure, a surgeon immobilizes the joint to reduce pain. Because the surgery limits patients’ mobility, it’s often performed on the smaller joints of the foot and hand.

Joint resurfacing (arthroscopic surgery). Surgeons remove such inflammatory particles as torn or damaged cartilage or bone from the joint. The procedure offers short-term relief.

Relaxation techniques. Meditation and yoga help relieve pain by relaxing muscle tension. Relaxation techniques also can help people manage stress and anxiety.

Tai chi. This ancient Chinese discipline stretches joints in a series of light, controlled movements. Its emphasis on deep breathing and inner stillness can relieve stress and anxiety.

Acupuncture. Some people have found pain relief through acupuncture. An acupuncturist inserts fine needles at specific points on the skin, penetrating just below the skin’s top layer. The needles do not draw blood or cause discomfort.

Osteoarthritis detection. Researchers hope to discover new ways to detect the disease in its early stages. Scientists are developing noninvasive urine, blood, and imaging tests that would detect changes in the tissues around joints.

Genetic tests. Scientists continue to search for more genes associated with the breakdown of cartilage production. Researchers have identified one genetic defect that leads to the early onset of osteoarthritis. They hope to identify more of these genetic markers to develop screening tests and genetic therapies to help prevent the disease.

Cartilage production. Preliminary evidence links a decreased number of cartilage cells to the development of osteoarthritis. Researchers are examining why cartilage cells die faster than new ones can grow, and several studies are examining the effects of certain proteins and molecules (like chemokines and insulin-like growth factor-1) that could stimulate growth in cartilage. A growth factor called human osteogenic protein 1 has been found to be very successful in stimulating cartilage protein production. Scientists hope to determine if vitamin C and certain chemicals called nitric oxide inhibitors can prevent cartilage damage.

Researchers also hope to develop monoclonal antibodies (cells produced by the immune system) that can identify the breakdown of protein molecules in the cartilage of people with osteoarthritis. Additionally, scientists are continuing to learn how certain enzymes called metalloproteinases break down and destroy cartilage. By understanding this mechanism, scientists hope to discover new therapies that can block cartilage destruction by these substances.

Joint replacement. To increase the range of motion after joint replacement, researchers are developing bioengineered, cell-based materials to replace the metal and cements currently used.

Acupuncture. The National Center for Complementary and Alternative Medicine (NCCAM) at Harvard University in Boston is conducting several studies to determine if acupuncture relieves pain and helps improve joint function. In one study, researchers are comparing the effects of acupuncture, fake acupuncture (or placebo), and patient education; another study will examine acupuncture in combination with exercise and physical therapy.

Glucosamine and chondroitin sulfate. A study sponsored by the NCCAM and the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) will evaluate the effectiveness of these supplements in relieving pain associated with osteoarthritis of the knee.

Magnetic resonance imaging (MRI). Research funded by the Arthritis Foundation is exploring the use of MRI to monitor very early changes in certain cartilage proteins called proteoglycans.

Medications. New medications may help improve the quality of life of people with osteoarthritis. New compounds called viscosupplements are injected into the joint to help provide pain relief for those with osteoarthritis of the knee. Researchers are studying a drug called doxycycline to determine if it may help prevent or slow down the progression of osteoarthritis. Scientists have found that doxycycline works against enzymes that break down cartilage.

Geneticists will continue to explore the role of genetic factors in the development and progression of osteoarthritis.

Researchers will determine if estrogen or hormone replacement therapy (HRT) help prevent the disease.

Scientists will continue to investigate new methods of stimulating cartilage production.

Researchers will study various complementary and alternative therapies to determine their usefulness in easing symptoms of osteoarthritis.