Consider this scenario: “Your test was out of the normal range,” your doctor says to you, handing you a sheet of paper with a set of test results, confusing numbers on a page. You start to sweat and your heart starts to race in fear that you are really sick. You feel your blood pressure increasing. But what does this statement mean, “Out of the normal range”? Should you be worried? The brief answer is that a result out of the normal range is a signal that further investigation is needed. Test results can only be understood once all the pieces are together. The doctor also has to consider such things as your personal medical history.
The term “normal range” is not used very much because it is can be misleading. If a patient’s results are outside the range for that test, it does not automatically mean that the result is abnormal. The terms “reference range” or “reference values” are more appropriate terms. To illustrate what I mean take a simple medical indicator as our heart rate. Most people know that the “average” heart rate is about 70 beats per minute. (If you didn’t know that, don’t feel bad). But how do you know what a “normal” heart rate is? We know this on the basis of taking the pulse rate of millions of people over time. You also might be aware that if you are a runner or physically fit, your pulse rate could be considerably lower-so a pulse rate of 58 could also be “normal.” Say you walk up a hill-your heart rate is now 120 beats a minute. That would be high for a resting heart rate but “normal” for the rate during this kind of activity.
The point: Exercise more! No just kidding but exercising is good for your health. The point: Your heart rate, like any medical laboratory test, must be considered in context. Without the proper context, any observation or test result is meaningless. To understand what is normal for you, your doctor must know what is normal for most other people of your age bracket, gender… and what you were doing at the time-or just before-the test or observation was conducted. What is “normal” for you may not be “normal” for someone else. As another example, if you’re a diabetic your glucose reading might be high, as opposed to someone who does not have diabetes. And that higher glucose reading may not be a cause for concern for your doctor.
The medical laboratory that issued the report will often draw attention to results that are abnormal or outside the reference range by setting them apart or highlighting them. For example, “H” next to a result may mean that it is higher than the reference range and “L” may mean “low”. Critical results that are dangerously abnormal must and will be reported immediately to the ordering physician.
A word to the wise-what not to do: Don’t call the client service department of the laboratory to ask them to interpret your results. They will only tell you to call your ordering physician. They are not trying to be mean to you or make you cry. Client Service departments are not in a position to interpret results for any patient since they do not keep medical history files on record for anyone. Call your personal doctor.