Aa
A
A
Close
Avatar universal
Severe Low TSH Normal Free T3 and T4
I have been on synthroid for about 15 years.  I am on 150mg at the present time.  My TSH levels are extremely low 0.016, but Free T 3 and Free T4 are normal levels. Am I on too much synthroid?  This is really confusing to me!  Can you please help? Am I considered Hypo or hyper thyroid?
Cancel
22 Answers
Page 1 of 1
Avatar universal
Hypo or hyper thyroidism should be defined by symptoms, not by results from blood tests.  This is especially true for TSH, which correlates very poorly to symptoms.  The best correlation, and the most important test, is free T3, with free T4 a distant second.  

My opinion is that the best way to treat a thyroid patient is to listen carefully to symptoms, and test and adjust the free T3 and free T4 levels as required to achieve a Euthyroid state, which means neither hyper nor hypo symptoms.  Many patients will have suppressed TSH results in order to get free T3 and free T4 to a level to alleviate symptoms.  Only you should  determine if you are taking too much synthroid,  by deciding if you are experiencing hyper symptoms.

Comment
Cancel
Avatar universal
Comment
Comment
Submit Comment
Avatar universal
Thank you so much for the the information!  Sooo..that being said, I can assume that if the symptoms are better, it is not dangerous to have extremely low levels of TSH when the T3 and T4 are at optimal levels.  
Comment
Cancel
Avatar universal
Comment
Comment
Submit Comment
Avatar universal
When you think about it, TSH is a Pituitary hormone that's purpose is to signal the thyroid glands to increase/decrease output of thyroid hormone.  Having a low amount of TSH doesn't do anything to the body.  It is only an indicator  of the level of T4 and T3 in the blood.  And in fact, only the free (unbound portion) of these hormones, free T3 and free T4, are biologically active in the body.   Free T3 is the most active.  It is four times as potent as free T4.  
So, unless a low TSH is signalling excessive amounts of the "Frees", confirmed by free T3 and free T4 tests, and by hyper symptoms, than there would be no concern.  My opinion is that tests for the "Frees" are much more reliable and useful for thyroid patients that TSH.
Comment
Cancel
Avatar universal
Comment
Comment
Submit Comment
Avatar universal
That makes sense to me!  I really do appreciate you taking the time to help.  I'm sure that I am not the only person on here that has been confused by this subject.  You have made it simple and I am greatful for that.
Comment
Cancel
Avatar universal
Comment
Comment
Submit Comment
Avatar universal
I have a different perspective than the one received re TSH's only function being to stimulate the thyroid to make more hormones.

TSH is very, very important for improving or upregulating the number of channels that absorb iodine into various tissues including breasts and ovaries.  And getting iodine into these tissues helps to protect them from environmental toxins and has shown to reduce cysts and other risk factors for developing cancer.

So, it IS important to monitor TSH and to keep it in the normal range.  Iodine will also improve TSH levels if they get too low.

All the best,
Dr. Alexander Haskell
Comment
Cancel
Avatar universal
Comment
Comment
Submit Comment
Avatar universal
I would love to learn more about this.  Do you have any articles about this I can look at?  I had a partial thyroidectomy and the 1/3 left is atrophied.  I take dessicated thyroid medicine so my TSh is always very very low, usually way below 1.  If I do not have a functioning thyroid do I have to be worried about iodine deficiency?
Comment
Cancel
Avatar universal
Comment
Comment
Submit Comment
231441 tn?1333896366
Hello,

I am also interested in this.

However many of us here now find that our TSH is extremely low (after years of being on thyroid med), regardless of where our FT3 and FT4 are.  Ie. My TSH is below detection range, but my FT3 and FT4 are well within the reference range.  Reducing my thyroid meds does not increase my TSH, it only decreases my FT3 and FT4.  We have tried. TSH only slowly increases when levels are below range (and by that time I am also feeling extremely bad).  

Btw I do have a pituitary microadenoma.  Previously had high prolactin levels which were supprssed with bromocriptine.  Don't know if there was any other effect from this.

Anyway, given what you've said, what would you recommend in this circumstance?

Comment
Cancel
231441 tn?1333896366
Comment
Comment
Submit Comment
231441 tn?1333896366
So abnormally low TSH (in the face of 'normal' FT3 and FT4) could represent an iodine deficiency?
Comment
Cancel
231441 tn?1333896366
Comment
Comment
Submit Comment
Avatar universal
Yes, please, cite links to studies supporting your hypothesis.

Also, please coment on HIGH TSH.  Is more better?  

Please explain how "iodine levels will 'improve' TSH levels if they get too low".
Comment
Cancel
Avatar universal
Comment
Comment
Submit Comment
Avatar universal
Sorry to have not checked in until now to give a little more feedback on a previous statement.
Again, TSH stimulates channels to absorb iodine into various tissues and iodide into thyroid cells.  Every medical physiology book calls the channels in thyroid cells, iodine traps, even though they absorb iodide.
The other channels are known as NIS or Sodium Iodine Symports.  TSH upregulates and increases the number of these channels, and so TSH is important.  Iodine has many important qualities when it comes to protecting breast tissue from environmental toxins and is known to reduce breast cysts and what's called benign breast disease.  
This is why iodine and iodide will cause an increase in TSH because the body wants to store these two valuable trace minerals.
More on this... I'll try to stay in touch more frequently.  You might like to visit my site which is on a thyroid condition known as Hashimoto's.  I'll be uploading some educational videos around February 10th, 2010.
Thanks
Dr. Haskell
Comment
Cancel
Avatar universal
Comment
Comment
Submit Comment
Avatar universal
Hello!

I just recently was able to get my endo to check my free t3 and t4 levels after four years, They showed my levels to be normal but my tsh abnormally low (.02). Four years ago, I was also diagnosed with a complex ovarian cyst which began to shrink once another doctor, who practiced holistic medicine, placed me on 50 mgs. of iodoral for a month, reducing it to 12.5 mgs. for the rest of his treatment. But upon seeing my endo, he took me off it because he discovered that I had Hashimoto's. Needless to say, the complex cyst has returned and has begun to grow larger.

I don't know what is the lesser of two evils. Do I begin using iodine again to fix the cyst or do I let the cyst grow and treat the Hashimoto's?  My endo believes iodine exacerbates my hypothyroidism. Please help!
Comment
Cancel
Avatar universal
Comment
Comment
Submit Comment
Avatar universal
How do I get my endocrinologist to agree with you?  I know how I feel and it was wonderful having enough energy and drive to enjoy life.  I smoke, which apparently lowers TSH and raises FT4 and Ft3, too.  Help!  I'm crashing.
Comment
Cancel
Avatar universal
Comment
Comment
Submit Comment
Avatar universal
Battling ongoing thyroid, very symptomatic, moods, weight loss, cant sleep, no appetite,   however, labs show extremely low tsh .015, while showing free t4 of 2.2 and free t3 of 5.7.   Also dxd with Graves Eye disease. although the Eye doc doesn't want to treat until the thyroid is stable.  My endo is not quite sure what to do, first question always "Are you taking your pills?"  DUH!!  I'm sick of being sick!!!  HELP
Comment
Cancel
Avatar universal
Comment
Comment
Submit Comment
Avatar universal
What are the reference ranges shown on the lab report for those test results?  What antithyroid med are you taking and what daily dose?  Are the test results representative of your latest dosage?
Comment
Cancel
Avatar universal
Comment
Comment
Submit Comment
Avatar universal
reference range:   free t4 .8-2.5   result is 2.2
                              free t3  (none on results)
                              tsh        .300 - 5.00

my does is 175  7 days a week
                  1/2 pill (87) 5 days week
This dosing has been tweeked too many times to count, as labs are constantly changing.  

Labs were done yesterday.  dose has not changed in past 2 months

Started as Hypo at age of 7, thyroid storm at age of 16,  radioactive idonetherapy at that time, but have not been stable since.  

Could they tryroid still be producing?  Could the radioactive iodine not have worked to kill the thyroid?
Comment
Cancel
Avatar universal
Comment
Comment
Submit Comment
Avatar universal
Now that I understand that you have had RAI and are on thyroid medication to replace the loss of your thyroid gland, it appears that you are being overdosed.  Free T4 does not need to be that high in the range.  Also, without being sure of your Free T3 level, it is also likely too high.  On what basis is your doctor deciding on your dosage changes?
Comment
Cancel
Avatar universal
Comment
Comment
Submit Comment
Avatar universal
I'll also add that I'm type 1, and that is a who other issue, A1C never can get controlled.  

My family is also a Autoimmune disaster,(myself and 2 siblings)  2 type 1 diabetics, 2 graves, 1 celiac, 1 gastroparisis,  1 addisons.

my gut says something is being missed!
Comment
Cancel
Avatar universal
Comment
Comment
Submit Comment
Avatar universal
Basis for the doctor's changes in med dosage?
Comment
Cancel
Avatar universal
Comment
Comment
Submit Comment
Avatar universal
The doctor changes doses based on symptoms,   I understand that the t3 and t4 are within reference range, however, being extremely symptomatic along with a severely low tsh is stumping???
Comment
Cancel
Avatar universal
Comment
Comment
Submit Comment
Avatar universal
From your symptoms and your Free T4 level I'd say that you need to reduce your med dosage.  Symptoms are the result of what is called tissue thyroid effects, which is determined by serum Free T4 and Free T3 along with some other factors that affect conversion of T4 to T3, transport into the cells, and the metabolism of thyroid hormone.

If your doctor is adjusting your med dosage based on symptoms, I don't understand how you got to that med dosage and level of Free T4, along with resultant hyper symptoms.  Just being within anywhere the ranges is not adequate for may people.  Many members have confirmed that relief from hypo symptoms required Free T4 at the middle of the range, at minimum, and Free T3 in the upper part  of its range, as needed to relieve symptoms.  Along with that it is important for Vitamin D to be about 55 minimum, B12 in the upper end of its range, and ferritin to be about 70 minimum.   Hypo patients are very frequently too low in the ranges for those.  Less frequently, but still a possible issue, is cortisol levels that are too high or too low.  

So I suggest that you should get tested for Free T4, Free T3, Reverse T3, Vitamin D, B12, and ferritin,   Once you know those we can tell what needs to be done with your med and dosage, and any supplementation needed for D B12 and ferritin.  Later it may be good to test for diurnal saliva cortisol levels (4 tests during the day), and DHEA-S.  If you can get these done and post results and reference ranges shown on the lab report we will be glad to help interpret and advise further.  
Comment
Cancel
Avatar universal
Comment
Comment
Submit Comment
Avatar universal
This is an ongoing thing, it goes up and down, which I understand, however, it's such dramatic swings, so the doctor is changing doses based on a lab pull, rechecking and swings.  I can't get stable.  My sister has been at the same dose for 2 years until recently when here ferritin was extremely low.  

I feel there is more to this, hate being symptomatic, and hate being asked if I'm taking my pills!!
Comment
Cancel
Avatar universal
Comment
Comment
Submit Comment
Avatar universal
Not clear on how the doctor changes your med dosage.  Thyroid med dosage should be gradually increased as needed to relieve hypo symptoms.  This typically means Free T4 at the middle of the range, and Free T3 in the upper part of its range, as needed to relieve symptoms.  Along with that it is important that Vitamin D be about 55 minimum, and ferritin about 70 minimum.  Cortisol is also important since low levels can cause problems, as well as high levels.  TSH level is totally irrelevant when taking thyroid med.  

So I don't understand how symptoms could be swinging up and down.  If you achieve symptom relief then no change should be made.  Have you gotten to that point and then symptoms returned, or new symptoms?  Or is the doctor making med dosage changes based on lab results?
Comment
Cancel
Avatar universal
Comment
Comment
Submit Comment
Your Answer
Avatar universal
Answer
Know how to answer? Tap here to leave your answer...
Answer
Submit Answer
A
A
Blank
Weight Tracker
Weight Tracker
Start Tracking Now
Thyroid Disorders Community Resources