Low T4, normal TSH

[ROJAS123]

My TSH levels are normal but my T4's are low.  Not sure what this means since if my pituitary glands are producing enough TSH what is happening to make my T4's low?
Doctor wants we to take a THS 3rd generation and a CBC and basic Metab panel.

I have all the symptoms of hypothyroid, depression, fatigue weight gain, joint pain, have cold hands and feet and got grey hair at a very early age as well as suffered infertility but she has not mentioned that and just told me to take these additional tests, so I am confused.
.
.  

[gimel]

TSH causes no symptoms.  Doctors like to believe that TSH is all they need to know to diagnose and medicate a hypo patient.  That is very wrong.  TSH cannot be shown to correlate well with either Free T3 or Free T4, which are the biologically active thyroid hormones.  Scientific studies have shown that Free T3 correlated best with hypo symptoms, while Free T4 and TSH did not correlate at all.  So a hypo patient cannot be dosed effectively based on TSH testing.  Studies have shown that the majority of hypo patients taking thyroid meds adequate to relieve symptoms find that their TSH becomes suppressed below range, which many doctors erroneously interpret as being hyperthyroid.  When already taking thyroid meds, TSH is basically a useless test.  

[pblichmann]

My personal TSH has to be below 1 or I have hypo symptoms. Everyone is different as to how they feel in the "normal" range. If you are having hypo symptoms then ask to have your meds increased. I am on Armour which works great for me, Synthroid lowered my TSH but T4 and T3 were still out of whack.

[gimel]

Welcome to the Forum.  Your English and grammar are great.  No problem there.

Having low TSH and also low Free T3 and T4 are indications of what is called central hypothyroidism.  Central hypothyroidism is due to dysfunction in the pituitary/hypothalamus areas, that results in relatively low TSH.  When the TSH is too low to stimulate the thyroid gland to produce adequate thyroid hormone, Free T3 and Free T4 will be too low in their ranges, resulting in hypothyroid symptoms.   Even though they may be within the low end of the so-called "normal' ranges, that does not mean it is adequate for all patients.  The ranges  are far too broad, due to the erroneous way they are determined.  Many of our members, myself included, say that symptom relief required Free T3 in the upper third of its range, and Free T4 around the middle of its range.  Scientific studies have shown that Free T3 correlated best with hypo symptoms, while Free T4 and TSH did not correlate at all.  

So, please post your actual thyroid related test results and their reference ranges shown on the lab report, so that we can better assess your status.  Also, have you been tested for Vitamin D, B12 and ferritin?  The reason I ask is that many hypo patients find they are too low in the range for those as well.

I am also providing a link written by a good thyroid doctor.  A good thyroid doctor is willing to test and adjust Free T3 and Free T4 as necessary to relieve symptoms, without being constrained by resultant TSH levels.  Symptom relief should be all important, not just test results, and especially not just TSH results.  I think you will find the info useful.

http://www.hormonerestoration.com/Thyroid.html

[larvik]

Hi,

Could you tell me more about that the pituitary doesn´t always work perfect. Because the piece about TSH and that you need to measure free t4 and free t3 is important.
I have relatively low TSH and low free t4 and in the lower end free t3 and no anti TPO so why do I have low free t4. They have measured my pituitary hormones and all 3 hormones are low except my growth hormone it is a little higher than max if 238 means anything to you. If I don´t take medicine my t4 will fall, but I do not feel well. Hope I have expressed my self correctly since I am danish, so please excuse my grammar and spelling. Hope you will answer best regards Ms Larsen

[gimel]

Thyroid related test results vary from one lab to another.  So it is important to always compare test results to the reference ranges listed on the same lab report.  If you will please post the reference ranges for those tests, members will be better able to comment on your test results.  

That said, I expect that your Free T4 is low in the range, which often is associated with being hypothyroid.  What symptoms do you have?  Symptoms are even more important than test results, in trying to diagnose a patient.

[Tete13]

My tsh blood test came back at 2.17 but my free t4 came back at.70 which is low. Does anyone know what this means?  At what point do you need medication?