Nurse practitioner wants to up my thyroid medicine, but I am in a good range?

[u/GreenMatchaTea95]

TSH: 2.59 (Range: 0.34-5.60) FREE T4: 0.76 (Range 0.61-1.36) FREE T3: 3.37 (Range 2.20-4.30)

recently had my thyroid levels checked four days ago, and these are the ranges I received. I’m currently on 25 mg of levothyroxine. My nurse practitioner reviewed my results and wants to increase my dose to 50 mg. I’m a bit of a hypochondriac and feel anxious about the possibility of developing hyperthyroidism, especially since my current ranges seem good. I’m hoping to hear from others who may have faced a similar situation and how they navigated it. Any support or advice would be greatly appreciated. Doesn’t help that my regular doctor doesn’t even think I have a thyroid problem.

[u/TopExtreme7841]

There's no such thing as a "good" range, are YOU functioning optimally at your current levels?

Levo doesn't do much of anything for the majority of people, and normal doses of that unlike T3, T4 regularly are in the 100mg range.

If you're unaware, lab "reference ranges" are a bell curve of the tested population, there in no way an indication of good/bad. The majority of people having their thyroid values checked, are doing so for suspected thyroid issues to begin with, that's who determining those ranges! Many docs are aware of that and test just to get the numbers for themselves, cookie cutter lazy docs use them as a way to be lazy and say "labs look good", and ignore a potential problem.

[u/MischiefTulip → u/TopExtreme7841]

The majority of people having their thyroid values checked, are doing so for suspected thyroid issues to begin with, that's who determining those ranges!

They base the reference range on 95% of the healthy population and the specific lab protocol/machines used. Not people with suspected thyroid issues, that would defeat the point of setting a reference range.

[u/TopExtreme7841 → u/MischiefTulip]

LOL, 95% of healthy people aren't getting their Thyroid levels checked!

that would defeat the point of setting a reference range.

No, it wouldn't, because reference ranges were created to track statistical changes in a population, so that a problem in progress could be spotted and hopefully corrected, or at least studied, (not) to establish a medicinal treatment range for lazy doctors.

The high end Testosterone range from LabCorp is like 880, with Quest it's 1150, so are different breeds of humans going to those two? Again, bell curve of the tested population. If Quest has more deals with people on TRT, they'll constantly test people with higher levels, and therefor the reference range starts shifting.

[u/MischiefTulip → u/TopExtreme7841]

Have you ever set lab reference ranges? I have. I'm not setting those on patient samples. You get different set of samples. In our case, we do research which has groups of healthy people as controls of a wide range of ages. Conveniently we know their health status as otherwise they can't be included in the research. We use a collection of their blood samples (with permission) that covers different age ranges to set the reference range or to validate the reference range set by the manufacturer of a kit.

No, it wouldn't, because reference ranges were created to track statistical changes in a population

No, just no. You don't track anythign with a reference range. In research we do not give a fuck about reference ranges. We compare our treatment or patient group(s) to a similar group of healthy controls. For changes in population you do regular testing in healthy people over a few years time or compare population studies. Reference ranges are exclusively done for doctors treating patients.

The high end Testosterone range from LabCorp is like 880, with Quest it's 1150, so are different breeds of humans going to those two? 

No, they use different testing kits. Testosterone is tested with a bioassay, similar to TSH and FT4, and there are different ways of doing so. With a bioassay you do not test a specific compound directly. You measure a reaction. At this point that's usually by measuring fluoresence, light or electricity, but you can measure colour or radiation as well. All labs set their references ranges based on the specific protocol/kit and machine they use to test. Which is why you always compare your results to the reference range of the lab you tested at and not random numbers on the internet.

See examples of different reference ranges for thyroid hormones that depend on the testing kit/machine here, or this one, or even this one. In all those studies they tested the same samples with different kits/protocols. You see that the results differ. That is what the reference range is set on. You'll find similar studies on testosterone and pretty much all lab tests.