Are Lab Reference Ranges Indicative of Optimal Health?


Many doctors will treat conditions only when there are overt deficiencies or lab values that are obviously out of range. But what do the lab ranges tell us? Are they optimal for the patient? What most people do not know is the lab reference ranges are about 95% of all values found in patients going to that particular lab and correspond to values that are within two standard deviations from the mean. The ranges are usually too broad and do not necessarily indicate the health status of someone for that particular value. For instance, looking at hormones, since people going to get labs drawn are generally suspected to have a deficiency or an excess by their doctor, the sample of people for the reference range for hormones are generally not at optimal health. This means that the reference range generated from this sample of people will not be looking at optimal health, and many people who are having symptoms of a hormone deficiency may not be treated simply based on their labs if their lab values fall in the “normal” range. Also, because about 95% of people will fall inside the reference range, that means that only 5% of people are caught with outright deficiencies or excess – this number is too low, given the population of people that are being tested! We see this happen quite a bit with thyroid and the TSH value. Many women suffer from “subclinical hypothyroidism,” where they are having symptoms of low thyroid like fatigue, feeling cold, slow digestion, dry skin, difficulty losing weight, etc., but TSH levels are still “within normal limits.” Many of these women will not be treated and suffer needlessly. Ideal ranges for individuals for optimal health, especially when looking at hormones, are often at the mean level of young adults – people generally feel better when their hormone levels are around the average level of young adults instead of within the lab’s “normal” levels. As naturopaths, we often have tighter ranges when looking at reference ranges for a lab value, because we know that the reference ranges are often too wide. For instance, when looking at TSH, we generally would like to see it around 1-1.5. Normal lab reference ranges for TSH can often go up to 4, but people can already be feeling symptoms when TSH gets up to around 2.5. Thus, if you are feeling like your health is not ideal but your labs look “normal,” it may be time to get a second opinion. You may have a deficiency or excess that is going undiagnosed and causing symptoms.  As a naturopath, I not only take into account your symptoms and lab values but look at the whole picture of your health, often checking other systems of the body that can be affected/related.

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