Many health screening tests are proven to save lives. Others are unproven but worthwhile. A few are not worth the risk of radiation or the wild goose chases that ensue. Proven tests include:

In the overview of preventive medicine, I discuss why preventive medicine is important and how you can evaluate whether a screening test is worthwhile. In this section we’ll go through the specific tests and procedures, and discuss the pros and cons of each.


Many think of vaccinations as something you give babies, but they critical for adults too. The older you are, the more important they become. I cover the details separately. Here’s a summary:

If you’re under age 60 and have no health problems, all you need is an annual influenza vaccine and a tetanus and diphtheria immunization every ten years. If you’re over 60, consider having a Shringrix to prevent shingles.

People with diabetes, lung disease, or other chronic illness, and those over 65, should have a Pneumovax to help prevent the most serious cause of pneumonia. Travelers to third-world countries have a whole additional set of needs.

Screening tests of proven benefit

Primary physicians perform a variety of screening tests, but only a few have ironclad scientific evidence of benefit. These have an incontrovertible scientific pedigree:

1. Pap smears. HPV (the human papillomavirus or wart virus) causes cervical cancer in women. Early in the 20th century, cervical cancer killed 40,000 American women a year. You catch HPV sexually. Different strains of the virus cause genital and anal warts, which can be annoying but are not serious. In most women, cervical cancer takes years to develop from the earliest abnormalities visible on a smear of cervical mucous. Smoking and HIV infection greatly increase the risk of getting cancer. Women need regular Pap smears after the onset of sexual activity or after age 21, whichever comes first. Depending upon the number of sexual partners, they should be retested every 1-3 years. Women over the age of 65 or 70 no longer need Pap smears unless they have more than one partner. Although a normal Pap smear can’t guarantee you don’t have cervical cancer, the frequency of missed diagnoses is very low.

2. Mammography reduces the risk of breast cancer in women over the age of 50. The reduction in risk is moderate: about 30% fewer deaths from breast cancer. Having a mammogram prior to age 50 is controversial, because fewer women that age develop cancer, and “false positive” tests (abnormalities on the image that don’t reflect true disease) are more frequent. You should have mammograms before age 50 if your mother or sister had breast cancer or you become menopausal or take estrogen. Interestingly, doing breast self-exams has not been shown to reduce cancer risk.

3. Colonoscopy reduces the risk of developing cancer of the colon, one of the most common types of cancer in the United States: 150,000 cases and 50,000 deaths annually. If you wait until you develop clear-cut symptoms, most often the cancer is incurable. Those over age 50 should have a screening colonoscopy every ten years. If a parent, brother, or sister has had colon cancer prior to age 60, the test should be done earlier. If a colonoscopy reveals polyps, they can be removed during the test. I’ve seen different estimates of the reduction of cancer risk but believe it to be in the 80-90% range. I believe doing this test has saved the lives of several of my patients.

4. Blood pressure checks should be done at virtually every visit to the physician. Hypertension is a silent illness that is lethal if not detected and treated. Your risk of a heart attack or other cardiac event doubles with every 10-point increase in blood pressure. Strokes and kidney disease are other consequences of high blood pressure.

5. Checking blood sugar regularly is of proven benefit in certain circumstances (for example, if you have high blood pressure) and unconfirmed in others. I feel strongly it’s important: the test is simple, and you can begin preventive measures if it looks like you’re heading in the wrong direction, even before the blood sugar elevation rises to the level of diabetes.

6. Similarly, checking cholesterol and other blood fats every few years can help identify those at increased risk of heart disease.

7. Women over age 60 should have bone density screening at least once to detect osteoporosis. Testing the density of your wrist or ankle isn’t helpful – instead, you should test your spine and hip. Bone density is also useful in men over 80 or 85, but there aren’t yet scientific studies proving its utility in men.

8. Everyone should have eye examinations every 2-4 years to detect glaucoma: increased pressure within the eye. Glaucoma may cause permanent vision loss before you realize it’s a problem, so regular screening is important. The eye pressure measurement requires special equipment available at the office of an optometrist or ophthalmologist.

9. Men age 65-75 who have ever smoked tobacco should have an abdominal ultrasound to rule out an aneurysm of the abdominal aorta, the main artery that supplies blood to every part of your body. An aneurysm is an abnormal enlargement of the aorta, similar to a bleb on a tire. If it’s big enough, you are at risk of a rupture of the aorta, which is usually sudden and fatal. It’s much easier to treat if detected before it ruptures.

Screenings that probably help but are unproven

1. A regular history and physical examination is the best way to develop a working relationship with your physician – but it has not been proven to save lives. Patients often have minor or annoying complaints they wouldn’t bother to tell a physician unless you and the MD take the time to sit down and address everything. Then it’s surprising how often this can help you feel better. Sometimes a “minor symptom” points to a serious medical problem that must be addressed early, before it becomes a crisis. In patients with ongoing medical problems, the annual exam is the only time available to review everything that’s happened during the year. You can spot trends that become apparent only when you review the entire year’s events.

2. Certain periodic lab tests may be of benefit, because they can detect problems that would otherwise not be apparent. These include blood tests for thyroid, blood count, kidney and liver function, and vitamins D and B12. These tests become more important as you become older.

Screening tests that may not be useful

1. The PSA (prostate-specific antigen) blood test is FDA-approved for every man over 50. But there’s no proof it’s helpful unless you’re at high risk for prostate cancer.

2. Ultrasound screening for narrowing of the carotid arteries in your neck is not that accurate and often leads to misdiagnosis of carotid artery narrowing.

3. Unfortunately, in people without symptoms, regular chest X-rays have been shown to provide no benefit in detecting or preventing illness, including lung cancer. There’s one group who does benefit from ultra-low-dose screening chest CT scans: people who’ve smoked a pack of cigarettes daily for at least 30 years or equivalent (two packs per day for 15 years), and some others who are at high risk for lung cancer.

4. A lot of other screening tests have been widely promoted but lack scientific validation. What do you do if you have an unproven test that shows a possible minor abnormality? Nobody knows, but it causes a lot of anxiety.