Predicting Your Medical Future

Breast exams: Less than 2 percent of breast cancers are diagnosed in women under 34. At this age, the American Cancer Society (ACS) says, a monthly self-exam and a similar exam by a doctor every three years may be helpful. Other agencies stop short of recommending either exam on a regular basis, but the tests can establish a baseline for later.

Pelvic exam and Pap smear: Good news—cervical-cancer rates fell 17 percent between 1998 and 2002. Since half of cases are diagnosed between ages 35 and 55, and it takes 10 to 15 years for HPV to develop into cancer, it's important to catch abnormalities before they turn potentially malignant. Start getting a pelvic exam and Pap smear at 21, or three years after becoming sexually active (whichever comes first), and get retested at least every three years until 65.

Complete blood count: This test, which examines red and white cells, hemoglobin and other blood components, can diagnose anemia. The disorder affects about 12 percent of women of childbearing age. Detailed bloodwork, such as chemical or metabolic panels, is unnecessary, says Dr. James King of the American Academy of Family Physicians.

Pregnancy: If you're trying to have a baby, you'll need many more tests. Ask your doc.

Testicular self-exam: Many doctors tell males older than 14 to check themselves for signs of cancer (usually lumps or swelling). The ACS says docs should check for similar signs as part of a routine physical. There's disagreement on that point. Dr. Barnett Kramer, associate director for disease prevention at the National Institutes of Health, says there's no need for doctor-administered exams; federal guidelines agree.

Blood pressure: Even in young adults, high blood pressure can increase risk of heart disease, kidney disease and stroke. Check it at least every two years, says Dr. Evangeline Lausier of Duke University.

Immunizations: "Once people turn 18," says Dr. Vincenza Snow of the American College of Physicians, "they think they're done with shots." They're not. They need a booster for tetanus, diphtheria and whooping cough every 10 years. College students may need a meningococcal vaccine; some colleges require them. STD tests: Chlamydia, gonorrhea and syphilis—the three most common sexually transmitted diseases—are all on the rise, according to the CDC.

Body-mass index: Have your height and weight checked as part of a regular physical.

Mammogram: According to a 2007 study by the National Cancer Institute and the U.S. Preventive Services Task Force (USPSTF), the number of women older than 40 getting mammograms every year or two is dropping. That may be bad news. Women at low risk for developing breast cancer should start annual or biennial mammograms at 40. Most health-insurance policies offer at least partial coverage. Those at higher risk—based on family history, weight, use of cigarettes or alcohol, early puberty or exposure to radiation —should start earlier, says the National Cancer Institute. Some groups recommend a baseline mammogram at 35.

Thyroid screening: Hypothyroidism causes few symptoms early on, but it can lead to obesity, joint pain, infertility and heart disease. Women over 35 should get checked every five years, says the American Thyroid Association. (It's not a universal recommendation: the USPSTF says the evidence for screening is inconclusive.) Since hypothyroidism is most common in midlife, catching it earlier than that will make it easier to manage, Lausier says. Women who want to get pregnant should also get tested, since a mother's thyroid problems can affect her fetus.

Blood pressure and BMI: From the age of 50, says Snow, doctors start screening for diseases in healthy people with no risk factors purely for the sake of prevention. Before that, testing should be much more selective. "Screening in general tends to be based either on age or risk factors," Snow says. At 34 to 49, age isn't the more important indicator. "Almost everything at this stage is going to be risk based. You have to have triggers," she says. That doesn't include height, weight and blood-pressure checks, however, which should be administered regardless of how healthy you are. Keep monitoring levels every one to two years. Rates of coronary artery disease have increased slightly for women in this age group, while men's rates have continued to drop, according to a recently published study, so everyone—not just men—should be vigilant about screening.

Nonfasting total blood cholesterol: High cholesterol is one of three important risk factors for coronary artery disease that you can do something about. (The other two are smoking and high blood pressure.) A complete lipid panel, which tests HDL, LDL and triglycerides, should start at 35 for men and 45 for women and be repeated every five years, according to federal health guidelines. People of both genders with risk factors for heart disease should start at 20.

Fasting blood-glucose test: This test, which determines how much sugar is in the blood, is often used as the first clinical indicator of diabetes. Although the USPSTF doesn't recommend that everyone get checked, the test can be used as a preventive measure in people over 40, or in younger people with heart conditions, obesity or family members with diabetes. The American Diabetes Association recommends a test every three years. Lausier says that in the past, a glucose level over 120 was a diagnosis of diabetes and anything below was considered normal; now, a result between 100 and 120 is categorized as "pre-diabetes." A third of pre-diabetics advance to the full-fledged disease; it's possible to reverse the trend if it's caught in time.

Eye exam for vision: Eyesight starts to deteriorate around this age, so get tested if you think it's declining, or at least twice between 30 and 39, according to Lausier. People who need glasses, contacts or other forms of vision correction should get retested every two to four years, says King.

Eye exam for glaucoma: This condition starts to appear from age 45. It develops quickly, but can be managed medically and surgically. People at high risk are nearsighted, have diabetes, are African-American or have a family history. If you're in one of these groups, get tested during your eye exam.

Mammograms: Mammograms are often recommended for women every one or two years after 40; by 50, they're an even better idea. Women with family histories should get a mammogram every year. In early 2007 the American Cancer Society recommended annual MRIs for those at high risk, too. (Not all docs agree with this policy.) Finally, women with family histories of either breast or ovarian cancer should get their BRCA1 and BRCA2 genes checked for mutations linked to both diseases.

Dual-energy X-ray absorptiometry: You won't need the DXA osteoporosis screen until 65, unless you have risk factors such as family history and low body weight. Women who don't use hormone therapy are also at higher risk. If you fit these descriptions, it's not a bad idea to get screened early.

PSA screening: The jury is out on whether all men over 50 should get this test for prostate cancer, which measures blood levels of prostate-specific antigen, a protein (see page 69). It's often used along with the digital rectal exam. Trials have been unable to find solid evidence for or against prostate-cancer screening. Part of the problem is that the disease isn't necessarily deadly. "It's often very slow-growing, and we're not sure how much benefit you gain from finding it early," says King. "A lot of men die of heart disease long before prostate cancer gets them." Widespread screening can result in false positives and unnecessary biopsies. Bottom line: consult your doctor and make up your own mind.

Colonoscopy: It's rare for the USPSTF to give a grade-A recommendation to a screen aimed at the general population. But colon cancer gets one: the agency "strongly recommends" screening for those over 50. There are four good methods. Colonoscopy, which makes use of a long, thin tube with a camera attached, may be the best known. Have your first one at 50 and another at 60. If you have a history of certain kinds of polyps or a family history of colon cancer, your doc may recommend more-frequent testing.

Flexible sigmoidoscopy: A sigmoidoscope is shorter than a colonoscope; it allows the doctor to see bleeding, inflammation, abnormal growths and ulcers in the lower third of the colon. Unfortunately, it can't reach the other two thirds. "Flexible sigs" should be performed once every five years.

Barium enema: This X-ray examination of the large intestine has some downsides: it's less precise than colonoscopy, and the USPSTF says there's "no direct evidence" that it reduces mortality rates. Nonetheless, if given every five years, it's acceptable in place of a colonoscopy.

Fecal occult blood test: This screen, given annually, is a subject of some debate. The USPSTF says there is "good evidence" that it reduces mortality from colorectal cancer. But King, along with many other docs, disagrees: "It doesn't tell us very much. By the time there's blood in the stool, it's too late." Your own doctor can help you decide if the FOBT is right for you.

Virtual colonoscopy: It's less unpleasant than colonoscopy, sigmoidoscopy and enemas, but it still requires what for many is the worst part: the clean-out. It's also no substitute: it doesn't work as well.

Other cancer screens: The short version: unless you have a family history, don't bother. The USPSTF recommends against widespread screening for pancreatic cancer, which is rare. It also recommends against bladder-cancer screens, which pick up false positives. The agency says the evidence is unclear for several other types of cancer.

Nonfasting total blood cholesterol: It's common for women to skimp on this test. But they shouldn't after menopause, when their risk of heart disease "rapidly approaches that of a man," says King. Get checked at 50 and every five years after, no matter what sex you are.

Mammogram: Breast-cancer risk increases each year after 65, but many doctors tell women to stop getting annual mammograms between age 70 and 85. The reason is simple, if a bit grim: it may be easier to live with breast cancer in old age than to treat it. Chemotherapy and surgery are hard on the body, and there's no good evidence that screening extends life expectancy at this age. One group, however, may be better off not stopping. A study last year suggested that breast-cancer survivors older than 65 can substantially cut their risk of dying of the disease by having a mammogram each year.

DXA: The gold standard for osteoporosis screening, this test measures bone density at the spine, hip or forearm. All women should be checked at 65. If their results look good, they can wait at least two years before their next DXA.

Pap smear: Women should have been getting it every year since 18. Now they may finally get to stop. "If you have a normal Pap smear at 65," says King, "you probably won't ever need another one."

TSH blood test: The USPSTF says there's not enough evidence for widespread screening, but not all docs agree. The American College of Obstetricians and Gynecologists says women over 65 should get a thyroid-stimulating-hormone check every three to five years.

AAA ultrasound: If you've ever smoked, you need to be scanned for an abdominal aortic aneurysm, which can develop over many years before bursting. Get checked once between 65 and 75.

Eye exam: Most docs recommend annual glaucoma tests after 65. But the USPSTF says there's not enough evidence to recommend that everyone get one.

Ear exam: The FDA says hearing loss affects one out of every four people over 65. Get a basic hearing exam from your primary-care doc every year.

Nonfasting total blood cholesterol: After 65, have your levels checked every four years (not every five, as before). King says it's OK to skip this test after 80, when "the side effects of the medications may be worse than the condition," he says.

Lung cancer: Smokers are at high risk—but even for them, the USPSTF says it's unclear if screening is worthwhile. The most sensitive test, low-dose CT, turns up more false positives than other tests.

Alzheimer's screening: Doctors can use questionnaires to detect Alzheimer's disease before symptoms set in. The tests are simple; one can be administered over the phone, another is known as the seven-minute screen. So why do many still advise against screening everyone for Alzheimer's? Because, says Kramer, even if patients are diagnosed early, there's currently no way to stop the disease (see page 64). Still, early diagnosis may help you make good use of the years you have left. If you have a family history or possible early symptoms—short-term memory loss, increased difficulty with daily tasks—ask your doc for a test. But don't expect one as part of a regular physical.