Hypothyroidism is diagnosed and monitored with a simple blood test. Learn what thyroid blood test results mean and how to understand TSH levels.
If your thyroid is overactive and producing too much thyroid hormone—due to disease or taking too high a dose of thyroid hormone replacement drugs—your pituitary senses that there is too much of the hormone circulating and slows or shuts down TSH production. This drop in TSH is an attempt to return circulating thyroid hormone levels to normal.
If your doctor won’t do the additional tests and insists on relying on TSH while you suffer symptoms, find a new doctor. Find a doctor who understands you are more than a lab number. There are good thyroid doctors out there. Here is a list of resources to help you locate a great thyroid doctor in your area. Do NOT settle. References: 1.
What Are Normal Thyroid Test Numbers? Normal thyroid stimulating hormone test results range from 0.4 to 4.0 milli-international units per liter of blood but may vary among laboratories due to differing measurements or test samples, according to MedlinePlus.
If your symptoms still point to a hypothyroid diagnosis, your doctor may measure the level of free T4 (the portion of total T4 thyroid hormone that is available to your tissues) in your bloodstream. Many people who are hypothyroid actually have high levels of TSH and low levels of T4—your doctor may refer to this as "primary hypothyroidism."
Symptom relief should be all important, not just treating your TSH level. If you are unsuccessful with that, then you will need to start looking for a good thyroid doctor. By that I mean one that will test and adjust your FT3 and FT4 levels with whatever type of meds are required to relieve your symptoms, instead of treating your TSH level.
It is best to have the test early in the morning. Experts do not fully agree on what the upper number should be when diagnosing thyroid disorders. Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your provider about the meaning of your specific test results.
Once the thyroid stimulating hormone makes its way to your thyroid, levels are largely dictated by the amount of T3 and T4 in your blood. When T3 and T4 levels are low, the body produces more TSH to stimulate the thyroid. But when T3 and T4 levels are high, the body produces less . Image source. Click to enlarge.
Thyroid Scale Overview. Dr. Rind's Thyroid Scale™ is a method of evaluating thyroid lab data (TSH, Free T4, and Free T3) relative to optimal values as well as each other to provide a clearer view of what is going on as opposed to simply looking at whether lab values are ‘normal’ or not.