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Correlation of TSH to Free T4
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Correlation of TSH to Free T4

Does anyone know what these labs would infer?
TSH - .8
Free t4 - .8
T3 uptake 39%

The endocrinologist blew me off, said everything was normal. My symptoms, extreme fatigue, dry eyes, dry skin, constipation, brittle nails, weight gain, carpel tunnel, muscle tendonitis and aches, constant headaches. my primary suggested i might have an issue with my pituitary gland. she started me on 50mg of Synthroid 35 days ago. i feel no change. i am having blood work done again today to see if there is any change in labs.
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Avatar_f_tn
Please post the ranges on your tests.  Reference ranges vary lab to lab, so you have to post both.

Often, low TSH with low FT4 is indicative of secondary (also called central) hypothyroidism.  It is a pituitary issue.  Although the thyroid may be capable of producing thyroid hormones, the pituitary is not producing enough TSH to stimulate it to do so.
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Avatar_f_tn
TSH - .8  RANGE : .46 - 4.68
FREE T3- .8 RANGE :.78 - 2.19
T3 UPTAKE- 39%  RANGE : 23.5 - 40.5%

does the borderline high uptake number confirm your theory? what is the Uptake anyway?
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Avatar_f_tn
Yes, as I suspected, your FT4 is very low - it's 0.8 with a range of (0.78-2.19), so it's right on the floor of the range.  Many of us find we still feel hypo until FT4 is around the middle of the range (1.48 on your range), so you're way below that.  

T3 uptake, despite its name is not a measure of T3.  T3 uptake is considered an obsolete test and of little value.  FREE T3 should be ordered.  Since it's rarely ordered any more, I have not idea about the subtleties of its interpretation.  

It looks like your TSH is not accurately reflecting your FT4 level.  With FT4 on the bottom of the range, we would expect TSH to be considerably higher.  The most likely cause of this is secondary hypothyroidism, which is actually a pituitary malfunction.  

The initial dose of meds we are put on is seldom what we end up on.  However, it is better to start out low and increase as tolerated.  So, your doctor has done the right thing there.  Once your labs are in, you will most likely want an increase.  It's not unusual for people to not improve or even feel worse until hormone levels increase to at least midrange.  Some of us have found that once FT4 stabilizes, FT3 will continue to rise afterwards for a while as the body rebalances.  Once FT3 and FT4 levels are both good, it can take some further time for the body to heal from being hypo, so symptoms can be a bit stubborn until that happens.

Once you have results, if you'd like to post them, I can see what the 50 mcg has done for you.  
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Avatar_f_tn
thank you so much for your feedback. just left the doctors office and results will be back on thursday. she is also expecting to increase dosage to 75 mg. . i have 3 small children at home under the age of 6 and so also suggested putting me on something called provigil to help with my fatigue until my thryoid stabilizes.
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Avatar_m_tn
With both your results being low in range it is not at all surprising that you have hypo symptoms.  This is just another reason why TSH test is an extremely poor test.  Unfortunately that is all most Dr's even look at.

Also something to consider it to have other tests done related to fatigue.  These include Vitamin D3, Vitamin B-12, Iron, and ferritin.  It is very common for many people to be low in one or more of these. especially it seems for people who are hypo.  So it is worth geting tested.

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Avatar_f_tn
I'm glad to hear she's most likely going to increase your meds.  

I don't know about the Provigil.  I've never heard of anyone taking  a "wakefulness promoter" when they have a thyroid problem.  When I was hypo, I almost had narcolepsy.  I wasn't tired as long as I kept moving, but if I sat down for more than a few minutes, I'd fall asleep.  With three little kids running around, I'm sure that would not be an ideal situation to say the least.  However, anything that just promotes wakefulness would seem to be something that could backfire easily if your thyroid hormones are low.  From the little I read about Provigil, it sounds like it keeps you awake but doesn't necessarily make you any less fatigued.  I also notice that it's approved for sleep disorders...couldn't find anything about its other uses.  
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my pcp had checked my Vit D. and it was a little low. I started a D3 and B12 supplement when i started the 50 mg Synthroid. i'm not really convinced about the Provigil either. But she said she has used it with many patients in the past who suffered from fatigue and that it really helped them a lot. not sure what to do about that.
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Avatar_f_tn
UPDATE: been on 75mg levo for about 6 weeks now, new numbers are TSH=.53, FT4=1.3. still feel weak and fatigue still present. do feel a little less tired, but not by much. thoughts?
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Avatar_f_tn
I'll assume the same range of 0.78-2.19 on your FT4???  It's come up nicely.  It was right on the floor of the range when you started, and it's at 37% now.  However, if your symptoms haven't resolved, there's plenty of room for an increase.  When on T4-only meds, it's usually recommended that you get your FT4 to around 50% of range.

One thing that many of us experienced is that once FT4 went up, it still took a while for FT3 to follow it up.  The whole process has to have time to ramp up again after being hypo, and many of us found our FT3 continued to rise even after FT4 was stable.  Would your doctor order FT3 if you requested it?  It's really important to see what FT3 is doing since it's the test that correlates best with symptoms.

If I were you, at this point, I think I'd be asking my doctor for an increase to get FT4 closer to 50% of range.  Next time you have labs, be sure to request FT3.  Once you're close to 50% on FT4, FT3 becomes even more important because then you have to start thinking that you might convert slowly and need to add a direct source of T3 to your meds, rather than just more T4.

Labs are looking up, and it seems your symptoms are just a little better, but you still have a ways to go and plenty of room in your labs to do that.

Have you discussed these with your doctor yet?  If so, what's his take?
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Dr.  increased dose to 100mg now.  Have not discussed T3 supplementation yet. Next blood check in 5 weeks, i will suggest it to her. A couple questions: 1- is there a correlation of body weight to mg of synthroid that would constitute a full dose? 2- if my numbers suggests a pituitary malfunction do i need an MRI of my head? 3- i still have daily headaches right between my eyes. can this be related?
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Avatar_f_tn
Good on the increase and the interval to the next blood work.

1) No, thyroid meds are only dosed by weight sometimes in the initial dose, when there's nothing else to go on.  Even then, that's a tenuous way to dose it.  Everything is so individual, and two people of the exact same weight, on the eact same dose can be hypo and hyper.  There's really no way around experimenting a bit on yourself.

2) Not necessarily.  It depends on the suspected cause of the pituitary malfunction.  If you have secondary hypo, for example, the only knowledge you're going to gain from an MRI is that you don't have a pituitary tumor.  I have a pituitary malfunction, and I've never had an MRI.

3) It could be.  Your pituitary is located just under your brain in the area you describe.  Pituitay tumors are  often removed through the nose.  However, I'm not sure that pituitary tumors typically cause pain.  Have you run that symptom by your doctor to see if he thinks it's related?  Also, don't quote me on this, but typically pituitary tumors cause high, not low, levels of TSH.  

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so here are my new labs. 100mcg synthroid for 4 weeks now.
TSH(.4-4.5)=.42, FREET4(.8-1.8)=1.2, FREET3(2.3-4.2)=2.8
i have appointment with new endo that specializes in metabolism. lets see what happens there. my doctor said that after i meet with her that we might supplement with T3. but that she is hoping that this new doctor will be willing to help look for an answer along side her. fatigue is better but cold intolerance, muscle weakness, joint pain, weight gain, still present. your thoughts...
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Avatar_m_tn
I agree with goolarra on everything she posted.  So, I'll let her respond to your latest lab results.  I just wanted to pass on this info that I thought might be of value to you.

A good thyroid doctor will treat a hypo patient clinically by testing and adjusting Free T3 and Free T4 as necessary to relieve symptoms, without being constrained by resultant TSH levels.  You can get some good insight into clinical treatment from this letter written by a good thyroid doctor for patients that he sometimes consults with after initial tests and evaluation.  The letter is then sent to the participating doctor of the patient to help guide treatment.  In the letter, please note the statement, "the ultimate
criterion for dose adjustment must always be the clinical response of the patient."

http://hormonerestoration.com/files/ThyroidPMD.pdf
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Avatar_f_tn
When you were on 75 mcg, your FT4 was 1.3.  However, I believe the range on that test was 0.78-2.19, the same as your first test posted above in your original question???  This FT4 has a new range?  If that is the case, then even though the raw number on your FT4 went down from 1.3 to 1.2, the percentage of range went up from 37% to 40%...not a lot of change either way.

There's no FT3 from the previous labs to compare to, but yours is currently at 26% of range, and the target for FT3 is upper half to upper third of range.  

I always think it's important to only make one change at a time so that you can isolate the effects of the change.  Right now, you have two alternatives:  increase T4 meds a little more to get to 50% of range or a little higher, or add in a little T3.

Many of us found that once FT4 became stable, FT3 continued to rise for quite a while afterward.  Conversion has to ramp back up.  

Even once FT3 and FT4 levels are adequate, symptom relief can lag since it takes the body time to heal from having been hypo.

If I were you, I think I might ask my doctor for one more T4 increasse to try to get it up closer to 50%.  If you have labs 4 weeks after that, you'll be able to compare your FT3 then to now and see it it's still rising (and tracking FT4 up).  And, you'll have that much more time to heal a bit and see how your symptoms are going.

The alternative would be to add in a conservative dose of T3 now and see where your labs and symptoms are after that.  

More than one way to skin a cat...
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Avatar_f_tn
Saw another Endo yesterday. Did some PIT labs. labs show PROLACTIN 6 (5-23),  LH 3.4 (1 - 11.4) normal but at the lower end. she is having an ACTH and Cortisol test done next week. will go from there. been on 100mcg synthroid for 6 weeks. Fatigue, cold intolerance, muscle soreness and dry skin much better. weight hasn't changed. will see my PCP again after ACTH and Cort tests. She said she would consider some T3 supplementation. what do you guys think about the PIT labs?
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Avatar_f_tn
just to clarify, i have been on synthroidfor 5 months in total. but have reached the 100mcg dose for 6 weeks now.
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Avatar_f_tn
Prolactin and LH are both on the low side of normal, with TSH, also a pituitary hormone, on the lower end of normal, too.  You could very well be looking at a pituitary issue...that would explain your low TSH.  

I'm glad to hear she's ordering more tests.  It's always a good idea to make sure adrenals are in good shape before adding T3.  
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Avatar_f_tn
Is a Pituitary problem progressive? meaning if untreated does it get worse over time?
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Avatar_f_tn
It depends on the cause of the pituitary problem.  Some are pretty static others can get worse.  

I lack an enzyme in my pituitary, so my TSH hovers around 20.0 all the time.  It changes slightly, but it hasn't gotten progressively higher.

On the other hand, a pituitary tumor, for example, might continue to grow.
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