A bone-density test is a way to measure the strength of your bones. The test, called a DEXA scan, is a kind of X-ray. Many people get a bone-density test every few years. The main reason to have the test is to find and treat serious bone loss, called osteoporosis, and prevent fractures and disability.

Most men under 70 and women under age 65 probably don’t need the test because:

Most people do not have serious bone loss.

Most people have no bone loss or have mild bone loss (called osteopenia). Their risk of breaking a bone is low so they do not need the test. They should exercise regularly and get plenty of calcium and vitamin D. This is the best way to prevent bone loss.

A bone-density test gives out a small amount of radiation, but radiation exposure can add up. The effects can add up in your body over your life, so it is best to avoid it if you can.

Who should get a bone-density scan?

For women over 65 and men over 70, DEXA scans are only appropriate for those with moderate risk of fracture or when the results will change the patient’s care plan.

Younger women and men ages 50 to 69 should consider the test if they have risk factors for serious bone loss. Risk factors include:

  • Breaking a bone in a minor accident.
  • Having rheumatoid arthritis.
  • Having a parent who broke a hip.
  • Smoking.
  • Drinking heavily.
  • Having a low body weight.
  • Using corticosteroid drugs for three months or more.
  • Having disorders associated with osteoporosis.

You may need a follow-up bone-density test after several years, depending on the results of your first test.

If you do have bone loss, you may be offered drug treatments.

The most common drugs to treat bone loss are Fosamax (generic alendronate) and Actonel (generic risedronate). These drugs have benefits and risks to think about and discuss with your health care provider. Common side effects include upset stomach, difficulty swallowing, and heartburn. Rare side effects include bone, joint and muscle pain, cracks in the thighbones, bone loss in the jaw, and heart rhythm problems. Other drugs used to treat bone loss also have risks, including blood clots, heart attacks, strokes, and serious infections. The treatments have limited benefits in some patients. Many people are given drugs because they have mild bone loss, but there is little evidence that these drugs help them. Even if the drugs do help, they may only help for a few years, so you may want to consider them only if you have serious bone loss. Mild bone loss is better treated with exercise, vitamin D and calcium.

The following steps can help you build bone:

Exercise. The best exercise for your bones is exercise that makes your bones carry weight. When you walk, your bones carry the weight of your whole body. You can also lift weights. Aim for at least 30 minutes of weight-bearing exercise a day.

Get enough calcium and vitamin D. They help keep your bones strong.

  • Aim for at least 1,200 mg of calcium a day. Eat foods high in calcium, such as dairy products, leafy green vegetables, and canned sardines and salmon. You may need a calcium pill each day.
  • Consider taking vitamin D if you are a woman in menopause or you get little sun. Take 800 IU a day.

Avoid smoking and limit alcohol. Among other things, smoking and drinking alcohol can speed up bone loss.

  • Try a stop-smoking program. Ask your health care provider about a nicotine patch or other treatments.
  • Limit yourself to one drink a day for women, and two drinks a day for men, unless you have medical reasons for tighter limits.

Try to avoid certain drugs. Some drugs can damage bones. These include proton pump inhibitors (common ones are omeprazole, lansoprazole, and pantoprazole), used to treat heartburn; corticosteroids; and some of the newer antidepressants. If you take one of these drugs, ask your health care provider about whether these medications are right for you.