Low TSH, everything else normal

I posted this a few days ago, but just cannot find it:
My first blood test was in 2006 because I had lost 9 lbs.  My TSH was 0.01, T4 total was 13.7 (H) and T4 free was 5.52 (H).  I took Tapazole for 3 months, gained more than I wanted and stopped taking the medication.  I have been going for blood work every 3-4 months and my T4 has always been in normal range.  My TSH has stayed low, with some increases.  June 07, TSH 0.012, October 07, TSH 0.014, January 08 dropped to 0.004 and my last test last week TSH went up again, was 0.020.  One doctor thinks I should have a brain MRI and another thinks I should take iodine to burn out the thyroid.  There's no way I could be on a pill daily, so that's out.  No one has answers why my TSH is low when everything else is within the normal range.  Do you have any idea what it could be?

[stella5349]

Are you taking any supplements?

Do you smoke?  

How much do you drink?  

Have you been on any birth control pills - estrogen? anitdepressants?

What other tests were done andy hormone panels?  
What's your age?

any pregnancies lately?

Was a blood sugar panel done?  Iron testing? Cortisol testing?

Was a TPO done?


I could ask a ton of questions - but lets start there.

[adr22367]

Are you taking any supplements?  No

Do you smoke?   Yes, about a pack a day

How much do you drink?   once a year on vacation :)

Have you been on any birth control pills - estrogen? anitdepressants?  No

What other tests were done andy hormone panels?   Just CBC, cholesterol and urine, no hormone panels

What's your age? 41

any pregnancies lately? No

Was a blood sugar panel done?  Iron testing? Cortisol testing? None

Was a TPO done? I don't see that on my paper, just TSH, T4, T3 Uptake and Free Thyroxine

[AR-10]

Hate to be a bother, but since you have a copy, could you list the result of the Free thyroxine, along with the test range?

A Free T3 would be even better, but that test was not run.

Your Free T4 and Free T3 can test at the top of the "normal" range even when you are hyperthyroid.

[adr22367]

No bother at all!  

Free Thyroxine 3.0
T3 Uptake 33
T4  9.2
TSH  0.020 (this went up from all previous tests)
I understand I have an overactive thyroid, but what I don't understand is why one doctor wants me to go for a brain MRI and another wants me to burn it out.  I go for blood work every 3/4 months and have an EKG twice a year.

[adr22367]

Sorry, forgot to put the range in

Free Thyroxine is 1.2 - 4.9  (3.0)
T3 is 24 - 39  (33)
T4 is 4.5 - 12.0  (9.2)

[stella5349]

Well I was hoping for some answers that would explain some things - I think you are - as you know- hyper.

I think the doctor that wants you to do iodine - just wants to burn this out so you go hypo. It doesn't sound as though he has the confidence you will go in remission with the hyperactivity. Ususally RAI is done in this case.

I can't explain why the other doc wants an MRI

[AR-10]

The doctor pushing for the MRI wants to look at the pituitary gland. Has he run hormone tests on your pituitary?

GH
ACTH
LH
FSH
Prolactin

Any of those tests run? They are hormones produced by the pituitary, as well as TSH. He is looking at your low TSH and wondering if it is a pituitary problem.

Your last test shows your Free T4 in a good spot, not high enough to drive your TSH low. but nobody is looking at your Free T3.

Your total T3 is not bad, but it doesn't really tell you what you need to know. Is your Free T3 high enough to make you hyper, or is it not? Total T3 will not tell you that.

I would ask for a Free T4 and a Free T3, because they are more acurate than the old tests, and I would persue the pituitary aspect and also ask for a saliva cortisol test on your adrenal glands. Adrenal fatigue can also cause a low TSH and low to normal Free T4 and Free T3.

With your TSH being consistantly low for a long time, your Free T4 and Free T3 should clearly show you as hyper. On the other hand, if you had a pituitary problem for a while now, your T4/T3 should be lower than they are.

The tests you present do not really show either condition, but they are not very good tests.

Do you have symptoms of hyperthyroidism? Heart problems, shakey (shaky) hands, anxiety, depression, muscle pain, trouble sleeping, fatigue easily?

How do you feel?

I wouldn't choose Radioactive Iodine Therapy until I knew it was required. Check your pituitary and Adrenals, and see if you have a false low TSH or if you are really hyper.

[adr22367]

Stella: Thank you :)  I'm going to look now for a 3rd doctor.  My Mom was hyper and went into remission 3 times before going hypo.  

AR-10: I haven't had any hormone tests, but yes, the dr. seems to think something is wrong with my pituiary gland because the TSH is low and others are within range.  If I don't find a new doctor soon, I will call the one I've been using and request more tests. I have no symptoms at all except for some anxiety that I've had since 97 due to a car accident.  
Thank you both so much for the advice :)

[adr22367]

I just spoke to my doctor about taking the other blood tests and he feels taking the brain MRI with contrast should be done first because it is a more sensitive test.  Should I just cave in and go, or find another doctor who will give me a script for the other blood tests?

[AR-10]

The MRI is a piece of cake. The contrast dye, that could be harmless, or it could be a health risk you have to consider. I don't know what kind of contrast dye they use for such scans.

I would ask, though. They never seem concerned about what the contrast dye is, because they assume you will only be exposed to it once, and what can one time hurt?

The last thing you need to here while you are laying on the table and they are putting in the IV is "Are you allergic to iodine?".

But an MRI would get a yes/no answer in short order.

[adr22367]

Thanks again AR-10 :)  I am going to call the diagnostic center tomorrow and ask what type of dye they use.

[adr22367]

Doing some research I found this, so will ask tomorrow if this is what they use:
http://www.csmc.edu/11089.html

When a pituitary MRI is done, scans are made, then a contrast dye is injected. A second set of scans are then made. The dye (usually gadolinium) makes it easier to tell the difference between normal pituitary gland tissue and tumors, infection or other abnormalities.

Unlike the iodine-based contrast dyes used in other tests, even a person allergic to iodine or shellfish can take gadolinium.

[Chinny111]

I have similar labs to yours, very low TSH, normal t3 and t4. I am told this is a rebound to hypothyroidism and can be misleading with the low TSH. I suggest talking to your MD about hypo. check forums on *****************

[adr22367]

Hi Chinny, I'm definitely not hypo.  My antibodies were 299, so I'm back on Tapazole once a day.  I'm going for blood work tomorrow and back to dr. next Friday.  He thinks I'll be on the medicine about 6 months to a year.  Last time I was on it I started gaining weight so stopped taking it.  I was on 15 mg. a day.  I'm only on 5 now, no weight gain, so hopefully this is it.

[HyperT77]

When I first started out my TSH was .  Both Free T3 & T4 were very high.  They have not checked my pituitary.  I was diagnosed with a Pituitary Microadnoma about 18 years ago.  But after menopause the prolactin levels, leveled out.  The Endo I see said he felt my pituitary was not the issue at this point because of the T3 & T4 levels.

I went from being very Hyper T to this past month, just at Hypo T.  He thinks that is due to my Thyroid still adjusting to the Methimazole.  His goal is to get my thyroid into remission.  Each month I feel better but don't like the yo-yo effect.

[adr22367]

I'm glad you're feeling better :)  I never had any symptoms except for the weight loss.  My T3 & T4 have been in range for 2 years now, but my antibodies are high and my TSH is always low.  As long as I don't gain weight with the Tapazole I'll stick with it and hope to go in remission also.  I'm going for blood work in a little while and hoping to see a little improvement even though it's only been 4 weeks on the med.