LOW TSH, LOW T3, LOW T4

[luckystars24]

I was put on 75mcg of Levo back in the end of June due to a struggle with high and fluctuating TSH for the last 13 years. (TSH at that time 2.936, free T3 2.75, free T4 .80) TSH had been as high as 13 in the past and as low as 1.497. Upon retest, two months later, my TSH was too low (.023) so my does was cut in half. Upon retest, 6 weeks later, my TSH was even lower (.005). Doctor took me off my meds and scheduled me for a thyroid scan and uptake and new bloodwork (still waiting on the scan results). My TSH is now .246 off meds completely for 8 weeks. However, my free T3 is now 2.17 (2.30-4.20 pg/mL) and my T4 is now 0.90 (0.70-1.80 ng/dL).

I have an appointment with the doctor tomorrow evening to discuss this, but was curious if anyone knows what this might mean? I've never heard of Low numbers on all of these tests. Normally my TSH is high and my other numbers are low.

Thanks!

[Barb135]

I don't really think there's a pituitary issue either; I simply think you were started on too high a dose AND that your doctor is placing too much importance on the TSH. As I said, there are several on here who routinely have very low TSH, including myself (have not had thyroid removed).

You might have felt great with high levels of FT3 and FT4; however, there can be adverse effects of allowing them to remain that high; AND there's a good possibility that had you been on a smaller dose, you would have found a lower level, at which you were just as comfortable.

Yes, I think 25 mcg is a good place to start, with retesting after a few weeks, then increase to 50 for a few weeks, then retest. Sometimes, it only takes a very small increase or decrease in med to make a huge difference in the way you feel.  

[luckystars24]

Thank you both for responding. My ranges for all my t3, t4 tests were T3 (2.30-4.20 pg/mL) and T4 (0.70-1.80 ng/dL).

The doctor totally discounted that the pituitary would cause my latest test results. I am going to get a second opinion next week I think. This doctor wants me to wait a week and get more blood tests done and then if I am still Hypo with my T3 and T4 levels then he will start me on levo again. I will suggest to him to start me out low this time (25 mcg you guys think?) When I was on 75mcg of Levo, he did check my T3 and T4 levels and they were really high, but I was feeling good, great actually, with no symptoms of Hyper. TSH was .005, T4 3.10, T3 7.60.

This doctor believes that I simply have silent thyroiditis and that it should go away in 4 to 6 months... but I have been dealing with this rollercoaster of numbers for the last 13 years. I just want to feel better!

I have had antibodies tested and I don't have graves or hashis... but i do have a family history... my mom is Hypo.

Thanks again for your opinions.

[Barb135]

What are the reference ranges for the FT3 and FT4 tests you had?  

It's not unusual for TSH to be low when on thyroid med.  Almost as soon as I was put on thyroid med, my TSH went to the basement and my doctor tried doing the same thing yours did - take away my med.  I felt horrible because I was so hypo, but he insisted that I was hyper - I ended up having to get a different doctor (and an endo).  My TSH currently runs at < 0.01 all the time.  While my pcp still wants to adjust based on TSH, I refuse to let him.  My endo handles the dosing for my thyroid med; and we pay no attention to TSH; we base my dosage on the FT3 and FT4 levels.  

If you were started on the full dose of 75 mcg, that might have been too much, too fast.  It's best to start out on a lower dose and work up, giving your body a chance to adjust properly to each new increase.  

I'd suggest that you DO need the med, but you need to start low.  It takes longer to get where you need to be, but eliminates the ups and downs of too much med, then no med, etc.

Have you been tested for antibodies to see if you have an autoimmune thyroid disease?  

[Super_sally888]

Hi Heather,

I will be interested in what your doctor has to say.  I hope he can look past the TSH.

When TSH is not useful, you need to medicate on the basis of FT3 and FT4.

FT3 should normally be in the upper 1/3 of the reference range. FT4 should be in about the middle of the reference range.  This is just a general guideline and it also depends on how you feel, but this is a good starting target.  

I believe that over time with chronic hypothyroid the TSH-pituitary link burns itself out.  For some this may happen early in the course of the hypothyroid and some later, some lucky people maybe never.  But it causes a lot of problems if a doctor is not prepared to look past TSH.

I have heard of some people on this forum (whose thyroid has been removed) have very low TSH and have their doctor (without testing FT3 and FT4) take them off thyroid meds because they were now "hyper".  We here, of course, advised them to have the proper testing....

When I was first hypothyroid (about 10 years ago) my TSH was a reasonable indicator of how my FT3 and FT4 stood.  However, in the last few years my TSH has dropped to close to zero and my FT3 and FT4 seem to move completely independently.  My doctor says I am 'unusual', but we no longer even test TSH and instead only test FT3 and FT4.

[luckystars24]

Hi sally,

thanks for your response. you are correct, I am feeling ridiculously Hypo. I am looking forward to my doctor's appointment today and know that I might need to seek a second opinion based on what he has to say. after my first test came back after i started the levo, he questioned whether or not i was taking more than one pill a day because it was "impossible" for my blood test to come back hyper. I was however FEELING AMAZING when my tests came back that hyper!!! I have never had a TSH so low without being on meds, so i wasnt sure why this new development for me when my test results used to be clssic hypo (high tsh, low t3, t4)

thanks again and I will let you know what he says!

heather

[Super_sally888]

Hi,

these low numbers would indicate secondary hypothyroid: this is where you get low TSH, combined with low FT3 and FT4.

This means that your pituitary is not properly detecting the thyroid hormone levels in your blood and is not increasing the TSH levels to stimulate the thyroid to put out more thyroid hormones.

In the case of secondary hypothyroid TSH is useless for management and medication should be dosed and adjusted purely using FT3 and FT4.

IF your doctor insists you are hyperthyroid on the basis of TSH alone, you must find another doctor.

How are you feeling?  You must be feeling pretty hypo.  Make sure the doctor listens to how you are feeling.

Please let us know how you go.