Low TSH and Free T4's

[Lizzie203]

I got a call from my gynecologist stating that my thyroid levels came back very low. We were trying to identify some of the symptoms since I have PCOS. My doctor stated my TSH level was at 0.29 and Free t4 level was at 0.24. I've been on daily 50mg of Cytomel since 2005. What all does this mean? I have symptoms of hypothyroidism (hair loss, fatigue, weight gain, muscle aches, etc). Everything that i read is very confusing. I'm going in to see my doctor on Thursday, but would rather have a heads up on what to ask for first. Also withe these levels, should I start seeing an endo instead of my Primary care physician

[Super_sally888]

Hi,

with low both TSH and FT4, it would likely indicate secondary hypothyroid.  This is where the reason is due to the thyroid is not able to put out enough TSH to make the thyroid work.

In this case you need to be treated on the basis of your FT3 and FT4 only, ignoring the TSH, to get your levels to mid to upper half of the reference range.  Adjustments should also be made on basis of where you feel good.

If your primary is good and competent with thyroid there is no need to see an endocrinologist.

[gimel]

First, I think that your dose of Cytomel must be 50 mcg, not mg.  Fifty mcg of Cytomel is equivalent to 200 mcg of Synthroid, so it is a fairly hefty dose.  Plus it is all T3.  Possibly this  dose of T3 is suppressing your TSH to the point that your thyroid (assuming you still have some thyroid function) is producing little or no T4.  At anhy rate you have to ask where should the T4 hormone be coming from when you are only taking T3 meds.  I don't remember anyone taking only T3.  I am used to seeing Cytomel used along with a T4 source.  

So this brings up all kinds of questions, such as what was the original diagnosis for your being hypo?  Why did the doctor decide to medicate with Cytomel only?  Have they tested you for FT3, along with the FT3 and TSH?  

[Barb135]

What is your Free T3 level?  I've heard of treating with just cytomel, but as gimel said, 50 mcg is a pretty hefty dose.  Usually when only a T3 med is used, it's given in very small doses, such as 5-25 mcg/day.  In addition to that, I can't imagine a doctor putting you on a T3 only med and not routinely testing Free T3 to make sure your levels are staying in line.  It stands to reason that your FT4 levels would be low if you are hypo, and not taking an T4 med.  

Would be interesting to know what your original diagnosis was, including lab results for TSH, FT4 AND FT3, plus "why only medicate with cytomel?".  

[Lizzie203]

All of my testing has been through my regular primary care doctor.  i've been on the 50 mcg of cytomel for about 3 years now.  When I was first tested in late 2005 my doctor said it was hypothyrodism.  She put me on 25 mcg of cytomel and 3months later had blood work and it was still low.  She then put me on the 50 of cytomel.  I want to say that back then my TSH was testing normal by my FreeT4 was low.  Since I've been on the 50mcg i have been tested yearly.  I went to my doctor because i was just feeling horrible constantly.  Extreme fatigue, continous weight gain, hair loss, chronic sinus infections, stomach problems.  I requested she test my thyroid due to the symptoms and it came back normal.  They I went to my gynecologist for my yearly and she wanted to test  my thyroid as well as sugars, testoterone levels.  All came back normal except my thyroid.  I'm very frustrated because i feel horrible all the time.  I've been complaining to my doctors for years (literally since 2003) about symptoms of fatigue, hair loss, inability to lose weight, and weight gain.  Started testing for thyroid problems in 2003, but they only did the TSH test which always came back normal.  Never did the free T4 test until 2005.  I'm a concerned about pituitary problems as this is what i have read from various cites (mayo clinic and a couple of other good sites).  Any advice on what to talk to my doctor about would greatly be appreciated.  I had to change my appointment to Friday due to scheduling an endoscopy for my stomach problems tomorrow.

[gimel]

Before getting too concerned with pituitary or anything else, I would absolutely insist that they check for FT3 and FT4 levels Friday, and post the results and reference ranges used by your lab, so that members can help interpret.  Be sure not to take your meds Friday morning until after blood is drawn.  I'm not sure why your doctor would want to give you a T3 only type med.  That can throw your T4/T3 ratio way off.  I went through that myself after switching from Synthroid to Armour.  My FT3 went up to the high limit of the range, but FT4 was in the very low end of its range.  I still had some lingering symptoms, so I switched to a combination of Synthroid and Armour, and now have a much better balance of FT4 to FT3.  I am still tweaking the dosage slightly , but symptoms are almost gone.