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Healthy Ranges for Medical Test Results

Take the guess work out of interpreting your numbers
Written by 
Amanda MacMillan
Canyon Ranch Reviewer: 
Updated on: 
December 31, 2013

When your doctor interprets your medical test results, she is looking to see whether they fall within set healthy ranges. You may have never concerned yourself with what those ranges are, instead simply waiting for the thumbs up or down from your physician to know how your health is faring. But getting a little more familiar with these numbers can help you better understand your health and have more productive conversations with your doctor.

What defines a healthy test result range for you will depend on your age, ethnicity and family history, among other factors, but there are some general guidelines provided by the National Institutes of Health (NIH) that are helpful as a starting point. If you’ve already gone for your physical exam, call your physician’s office to get a copy of your test results so you have a basis for your next discussion with your doctor. She can shed more light on whether or not you need to take steps to improve your results.

And remember: What is healthy for you is dependent on far more than a few numbers can explain—and on far more than how you do on one test alone. It’s important to evaluate how your results change over time because while you may be in a "normal" range, a significant increase or decrease may be a cause for concern.

Blood Pressure

Blood pressure—the force of blood against the walls of your arteries—should be checked annually. Those who have a family history or personal history of high blood pressure or pre-hypertension, heart disease, diabetes or kidney disease should be checked at every doctor’s office visit. Blood pressure is determined using two measurements: The first is systolic blood pressure and it measures the pressure in the arteries as the heart contracts (beats). The second is diastolic and it measures the pressure between beats, when the heart is relaxed and filling with blood. When those numbers are high, it suggests the heart is working too hard to pump blood throughout the body.

A healthy blood pressure measurement is one where the systolic (top) number is less than 120 and the diastolic (bottom) number is less than 80. When that is not the case, you are considered to have prehypertension, the precursor to high blood pressure, or hypertension itself. Compare you results:

Prehypertension Systolic 120-139 OR Diastolic 80-89
High Blood Pressure - Stage 1 Systolic 140 or higher OR Diastolic 90 or higher

High blood pressure increases your chances of developing heart disease, stroke and kidney failure. African Americans are more likely to develop high blood pressure more severely and at an earlier age; people with a family history of high blood pressure, who are overweight or who smoke are also at increased risk.

Cholesterol

It’s also important to have your cholesterol checked at least every five years, starting at age 20. (You may need to be tested more often if you have risk factors for high cholesterol, including cigarette smoking, high blood pressure or a family history of high cholesterol or early heart disease.) Cholesterol is measured with a blood test called a lipoprotein profile, which provides four important results:

  • Total blood cholesterol.
  • LDL, or “bad,” cholesterol.
  • HDL, or “good,” cholesterol. 
  • Triglycerides, a measure of fat in your blood. 

The emerging gold standard for screenings also includes tests for apolipoprotein A1 and B levels, which correlate with HDL and LDL levels, respectively, and can give your doctor more information on how best to treat you. You might consider asking for these newer tests if you're very concerned about your cardiovascular disease riskif you have a significant family history of the disease, for example.  

Based on the newest guidelines, your doctor will consider your cholesterol numbers alongside other risk factors, like your blood pressure and age, to determine your overall risk for heart attack and stroke. 

Bone Density

This test uses a machine called a dual-energy x-ray absorptiometry (DEXA) scanner to measure the strength and mineral content of bones in the spine, hip and forearm. National guidelines say that women and men should have a bone mileral density test (BMDT) at age 65 or 70, respectively, or earlier if they have risk factors for osteoporosis such as a family history of the disease or enter into early menopause. At Canyon Ranch, we suggest that women consider screening prior to age 50 because they already have a 50 percent lifetime risk of developing a fragility fracture by then.  

Bone mineral density tests have two results: Your T-score and your Z-score.

  • Your T-score is your bone density compared to that of a healthy young adult of your gender, and it is measured in standard deviations from that average. A T-score is used to gauge early signs of bone loss or overt osteoporosis. A T-score between -1.0 and -2.5 indicates osteopenia, the predecessor of osteoporosis. T-scores of -2.5 and below diagnose osteoporosis.
  • Used less often by most physicians, your Z-score, on the other hand, compares your bone density with the average score for your gender, age, race and weight. A score above -2 is considered normal; anything below that may suggest that your bone loss may be due to something other than normal aging. However, this score can be a bit misleading, so diagnoses of osteoporosis are based primarily on T-scores; think of your Z-score as another piece of information that your doctor can use to gauge your overall bone health picture.

Blood Sugar

Your doctor may recommend a fasting blood glucose test to measure the amount of glucose in your blood; this is usually to help identify or rule out type 2 diabetes. Up to 100 mg/dL is considered normal for fasting blood glucose, although some laboratories use different scales. Levels between 100 and 125 mean impaired fasting glucose (a risk factor for diabetes), while a score of 126 or higher means a diagnosis of diabetes.
 
Another type of blood sugar measurement, called the Hemoglobin A1c test, can also be used to diagnose diabetes. An A1c level of 5.7 to 6.4 indicates pre-diabetes. An A1c level of 6.5 and above indicates diabetes.
 

PSA

Many doctors—although not all—recommend annual screenings for prostate cancer for men age 50 and older. (Those at higher-than-normal risk may begin screenings even earlier, at 40 or 45.) The prostate-specific antigen (PSA) test can determine the amount of a specific protein in your blood, produced by the prostate gland and elevated in those with prostate cancer and other non-cancerous conditions. The higher your score, the more likely your doctor will want to conduct further tests to explore your situation further.

A PSA score below 4.0 ng/mL is considered normal, but studies have found that prostate cancer can be present even in people with lower scores. Because of this, it may be more appropriate to follow the trends in your PSA score over time. However, there is no consensus in the medical community whether PSA testing should be done at all. Ask your physician if he recommends this test.

"Your numbers, together with your personal and family medical history, create a wonderful basis for a medical review and wellness discussion."
"Your numbers, together with your personal and family medical history, create a wonderful basis for a medical review and wellness discussion."
Reference(s) 
American Heart Association
Centers For Disease Control and Prevention
Heart and Stroke Foundation
Mayo Clinic
National Institutes of Health
About the author 
Amanda MacMillan is a health writer and editor in Brooklyn, New York. Her work has appeared in Prevention, Runner's World, Health, and Whole Living magazines.