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4524270 tn?1355878350

Should I be concerned with this lab range?

For the past several years my FT4 has been below range, around .60 or .61, with a range of .81 - 1.37. Now my hospital has changed The normal range to .61-1.37 and my last result of .61 reads “normal.”

Pretty sure my dr knows better. It is way lower than optimal. Does this mess with the math for optimum numbers? I can’t recall how to figure it out.
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Avatar universal
What was your cortisol level and reference range?
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4524270 tn?1355878350
Thanks for all the replies. I’m hypothyroid as far as symptoms and I just spent two or three months on half a dose clearing RT3. I’m back up to four grains NDT and 50 mcg cytomel, divided  into three doses. I should be checked again in March. I have had Rt3 two or three times over the last five years while having abelow range Ft4. Too many symptoms to list but I know what they are. I’ haven’t had relief from symptoms.

My next lab should hopefully tell me if I’m
near optimal.  Last checked,  b—12 was upper, D, optimal, ferritin was higher than optimal. Cortisol normal in Dec.  Antibodies dropped from about 6800 to 68 over the last four years.

My hospital just switched to Sparrow labs. Thank you for all the help.
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1756321 tn?1547095325
QML changed the reference range of free T4 from 10 - 20 pmol/L to 15 - 30 pmol/L. O_o  My free T4 was "normal" at 25 pmol/L. My suppressed TSH, high T3 and hyperthyroid symptoms said otherwise. I switched to a other lab as QML have the worst reference ranges. Their vitamin D range states normal above 49 nmol/L (19.6 ng/L). My bone pain said other wise!

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Avatar universal
Hi Alittleblues,

For freeT4, most people feel better and have fewer hypothyroidism symptoms when they are in the top 50% of the normal range (and freeT3 is optimal for most people when it is in the top 1/3 of its range).  I guess the main question for you is "are you having hypothyroidism symptoms at your current level?".

Your FT4, even if 0.61 is "in range" is at the very bottom of the range, and I would be surprised if you weren't having hypo symptoms.  Is FT4 the only method your doctor is using to measure thyroid hormone?

T3 is the active form of the thyroid hormone that is taken up and used by cells throughout the body.  Depending on what medication you are taking (if any) you may be getting enough T3 - natural desiccated thyroid hormone I believe has the ratio of T4 to T3 at 4:1.  I take levothyroxine which is just T4.  Normal blood levels of T4 to T3 are around 11:1, so as long as your cells are getting enough thyroid hormone and that hormone is functioning properly in the cells, then you could have low T4 but still adequate functional levels of T3 in your cells.

All people are different and respond differently to thyroid hormone, but for comparison, my latest results for FT4 are somewhere above 1.34 (range 0.8-1.8), and I am still having hypo symptoms even though I'm now above that 50% level (and my endocrinologist has just increased my thyroid hormone dosage).  I've seen my FT4 at 1.2, 1.24, and 1.34, and I've had a ton of symptoms at all of those levels, even though it has always said "normal" on the test result for freeT4, and my endocrinologist keeps increasing my dosage.

Anyway - I hope this helps.  freeT4 is optimal when in the top 50% of its range (but for me, I'm in that range and still hypo).  If you are feeling a lot of hypo symptoms, you should probably talk to your doctor and try to see what can be done to get your freeT4 levels up.
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3 Comments
Referring back to the definition of hypothyroidism as "the clinical state resulting from suboptimal T3 effect in  any or all tissues of the body", it is very important for you to be tested for Free T3, and I'd even request a Reverse T3 at least initially.   Hypo patients taking T4 meds often are unable to get their FT3 level high enough to relieve symptoms, without having to raise their FT4 to the top of the range, or beyond.     This is usually a problem with the doctor because a higher,  once daily dose of T4 med tends to suppress TSH for almost a day, which tends to reduce conversion of T4 to the T3 needed by all tissue throughout the body.  Many doctors don't recognize that a suppressed TSH in the untreated state is totally different from a suppressed TSH due to T4 therapy.  The single dose of thyroid med has a different effect on TSH than the continuous low flow of thyroid hormone in the untreated state.    

So you need to get the doctor to understand the need to add some T3 to your meds, and get your FT3 level high enough to relieve those hypo symptoms.  In addition hypo patients can be affected by low cortisol and are frequently deficient in Vitamin D, B12 and ferritin.  D should be at least 50 ng/mL, B12 in the upper end of its range, and ferritin needs to be at least 100.  Deficiencies in any one of those can contribute to symptoms.   Do you think you can get your doctor to accept the need for the additional tests and the need to treat clinically?  If not,  you can find information to help persuade the doctor by clicking on my name and scrolling down to my Journal and reading the Overview of a paper on Diagnosis and Treatment of Hypothyroidism: A Patient's Perspective.  A copy of the Overview might help with the doctor since it also has a link to the full paper with all the supporting scientific evidence for all that is recommended.  
Thanks for the information.

I currently take calcium plus vitamin D3 daily, vitamin B12 daily or every other day, and iron supplements a few times a month, but I haven't been tested for iron, B12 or vitamin D as far as I know, so I can see if my doctor will add those to my next labs (or the following if it is too late, I believe lab orders have already been sent to me, and I don't know if I can change this coming round).

I take calcium at least 4 hours after my thyroid hormone, I don't take a multivitamin, just individual supplements of calcium, B12, and iron as needed.  I don't eat mammals, so that probably doesn't help with my iron and I'm not sure how it impacts B12 - I know vegetarians frequently need to supplement B12, but I don't know about pollo-pescetarians.  I do feel more energetic when I take B12 (still hypo, but slightly less fatigued).  I started B12 after experiencing odd breathing issues while running (not anything I worried about, just felt like I was breathing really funny), and have not had problems since starting B12.

I will contact him about testing for T3 - I haven't seen my latest results, he told me over the phone numbers were "in range" but then increased my dosage of levothyroxine without asking if I was still having symptoms, which makes me think my TSH is still high.  My freeT4 was 1.44 when I was first diagnosed with a thyroid issue in March 2018 (multinodular goiter), and my TSH was 3.44 which was considered "in range" so they would not treat me even though I had lots of hypo symptoms.  (My freeT3 was 3.2 (range 2.0-4.4) which I now know is not a desirable level for FT3).  I'm not even back up to 1.44 yet for Ft4, so I'm not surprised I still have a lot of symptoms.   I am also apparently a "bad absorber" of T4, so it has taken several increases to get freeT4 even above 50% of the range for me (had thyroid removed in two surgeries, one in June, one in August 2018).  My thyroid hormone is being managed now by an endocrinologist, and he seems much more willing to listen to my symptoms as well as look at tests compared to my PCP and ENT, but I also have no thyroid now so maybe that helps with his willingness.

Anyway, thanks a lot for your advice.  I'll probably wait to see what my actual current numbers are from this last test (should be coming in the mail), then contact him and see if we can add the new tests or at least consider adding T3 medication if my T4 is getting up higher in the range and still no improvement of symptoms.  My doctor seems very willing to add additional tests (calcium, magnesium, renal function, celiac antibodies - I didn't ask for any of these but I think he just wanted to make sure they were ok), so he will probably add those tests suggested as long as they can be justified (I'm sure ferritin and B12 and any thyroid hormone can be easily added to my lab orders).

This definitely gave my something to think about.  Thanks again.
You ae very welcome for any info I can provide.   If you have time to read the Overview I mentioned, you will note that,  "Testing should  include  FT4, FT3 and RT3.  The main value for TSH testing is only to differentiate primary from central hypothyroidism.  Cortisol, Vitamin D, B12, and ferritin levels should also be tested due to their potential impact on TISSUE T3 EFFECT and resultant symptoms, which best reflect the patients’ concerns."    All are important for you you to know so that effective treatment can be implemented.
Avatar universal
I am sure the change was done by the laboratory, not the hospital.   Ranges for FT4 and FT3  are established at the lab by first using a kit provided by the test equipment manufacturer to validate test consistency.    Then the lab uses statistical analysis of their database of thyroid tests to establish the reference range.   Of course they have no way of knowing if the test results are from people with or without hypothyroidism, so they exclude the top and bottom  2.5% and call the remaining 95% "normal".  So the test database is not from patients with no known thyroid issue.  Instead it includes physician ordered tests for patients.  As a result the reference ranges for FT4 and FT3 reported by test laboratories are too broad and skewed to the low end.    Perhaps the change in the range was due to a re-calculation for a database that has shifted due to more data coming from hypothyroid patients.  

Hypothyroidism can be defined as "the clinical state resulting from suboptimal T3 effect in  any or all tissues of the body".   For dosage adjustment it is useful to know both FT4 and FT3 levels, but there are numerous additional variables involved, so that each person is different in how their body  responds to serum thyroid hormone.   Diagnostic and treatment decisions for hypothyroid patients should be based on signs/symptoms, not just laboratory tests.    There are no lab tests capable of defining a person's thyroid status.   That is what you have to get across to your doctor.    

In order to do that I suggest that you can use a questionnaire like the following to identify your symptoms and give a copy to the doctor and request to be treated clinically, for symptoms.    

http://www.hormonerestoration.com/files/Hormquest.pdf

If the doctor questions this approach give him a copy of the Overview in my Journal.   It includes a link to all the supporting scientific evidence included in the full paper on Diagnosis and Treatment of Hypothyroidism" a Patient's Perspective.  
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