When you go to get the results of a blood test you have had done by your doctor you may notice that they never talk about anything unless it is “out of range” and highlighted from the laboratory that performed the test. This is because many doctors don’t do anything to help prevent a disease or help people maximise their health, and rarely know what the optimal level for a certain marker should be. To monitor your health correctly, prevent disease, see any early warning signs, or reach your maximal potential, you need to know a few things about blood tests and what reference ranges really mean.
References ranges that the doctor goes by are produced by the laboratory company they use and consist of 95% of all values that are found in patients tested by that particular laboratory. “Normal range” is basically a statistically method which includes everyone tested except for the very highest and lowest values (2.5% of each) which gives the 95%. If you look at who actually gets blood tests done, it is mostly people that are sick, it’s rare that healthy individuals go to the doctor to get a blood test done. So, in essence reference ranges are an average of all the sick people of the population who have their blood tested by a certain laboratory. This is why you could still be sick or not feel your best even though your results come back as “normal”. As the health of our population declines the laboratory adjusts its reference ranges so what may have been a healthy range 20 years ago may be far from that today. If you think about it does this mean the new level is truly that of health or was it that of 20 years ago?
A better approach is to know what the optimal level of a certain test should be. This means that you could be “in range” and not have an actual disease but you know by the result that you could have a potential issue and need to work on this area. For example, let’s just say the range for fasting insulin is between 2 and 10. After 10, this is where your doctor tells you you have diabetes. Your test results come back at 9. Your doctor tells you everything is normal and in range. At this point you already have insulin resistance and are on your way to diabetes but it isn’t yet addressed because you are still “in range” which to most doctors means you are healthy. Now, if the optimal level is between say 2 and 4, and your results came back at 9, we would see this as a sign that something isn’t right and ask you some questions about your nutrition and lifestyle. We would then make adjustments to your diet, replenish any nutrient deficiencies, start exercising, and improve sleep for example. By doing this you could lower the insulin levels and prevent the progression into diabetes. In fact we would address this much earlier, if we saw a pattern of your results increasing slightly overtime, we would ask these questions before it even got to such an extreme level. Even at a level of 5, it would be something you could address and closely monitor. A doctor would say you were very healthy at that level and leave you to continue on your way.
A lot of the time the optimal level for an average person of average weight and height corresponds to mean levels found in young healthy adults.
Even by using an optimal reference range you don’t have all the information you need. You have to take a thorough medical history of the client or patient and actually correlate the test results with the clinical signs and symptoms that the client presents. Everyone is individual so what may be good for someone may be terrible for another. Things such as body size, age, gender, activity level, and stress level to name a few, can all have an impact on what is optimal for that particular person. A true optimal level then is one that allows the individual to be free of complaints and physical signs. This is why is takes an experienced medical professional to look at many factors the patient is presenting with and not just treat a lab result.