Thyroid issue

[tam1947]

I'm not sure I understand the entire Thyroid / Synthroid issue. I have been on Synthroid for many years. About a month ago, in my annual physical, my TSH came back 0.02. Very "low". My doctor decreased my dose from .175 to .150. Does Synthroid INCREASE TSH or DECREASE it? I was told that my TSH range should be 0.40 to 4.50. No other medication or life style issues. I take it every morning when I awaken and well before I eat anything



This discussion is related to Increased TSH on increased dose of Synthroid.

[goolarra]

Synthroid should decrease TSH levels.  TSH is counterintuitive:  When TSH goes up, you are more hypothyroid (low thyroid); when it goes down, you are more hyperthyroid (high thyroid).

What were your FT3 and FT4 levels before the decrease (please also provide reference ranges from your own lab report)?  Were you having hyper symptoms on 175 mcg?

TSH is very volatile and can change by as much as 70% just depending on the time of day the blood was drawn.  For that reason, it should never be used alone to manage thyroid meds.  

[Barb135]

Synthroid lowers TSH.  Thyroid levels are counter intuitive.  TSH is a pituitary hormone that stimulates the thyroid to produce thyroid hormones.  As thyroid hormones go down, TSH goes up; as thyroid hormone levels come up, TSH goes down.  

Synthroid is a thyroid hormone, so it causes an increase in thyroid hormones, which causes a decrease in TSH.  The problem is that not everyone who has a low TSH needs to have medication decreased.  

Is TSH the only thyroid test your doctor is ordering?  S/he should also be ordering Free T3 and Free T4, which are the actual thyroid hormones.  Free T4 is a storage hormone that must be converted to Free T3 in order to be used by the individual cells.  Synthroid is a T4 only medication, so it's providing only T4 hormone, which must be converted to T3 prior to use.

Many doctors only go by TSH and they think that if TSH is too low, the patient is over medicated, but you're only over medicated if you have symptoms of hyperthyroidism, which could include rapid weight loss for no reason, diarrhea, mood swings, hand tremors, etc.

Your lab is using an old range for TSH... over 10 yrs ago, AACE recommended that the reference range for TSH be changed to 0.3-3.0, but labs and doctors have been very slow to respond.  Most people with TSH over 3.0 have symptoms of hypothyroidism.

[tam1947]

Thank you. No need to go further. You answered my question. I have never had "obvious" symptoms. Just the annual or more often blood labs I get done.

[tam1947]

Wow. I am learning so much. I just want to have the "energy" that I think I may not have due to Thyroid issues. Sleepy and tired etc. The lab was Quest and I just pulled up the results before posting (was from a month ago). Code desc is 899 TSH - whatever that means. "Value" was 0.02 - L - reference range was 0.40-4.50 so yours looks much better. I  am a 67 year old man. Still. very low number. And, as I understand it, LOWERING the dose is the correct thing to do do to attempt to raise the TSH level. Thanks so much

[Barb135]

Not everyone with a low TSH needs to have their dosage lowered.  For instance, my TSH stays at < 0.01 and I, sometimes, actually need my dosage increased, not decreased.  

In addition to testing for TSH, your doctor should be testing Free T3 and Free T4, which, as I noted above are the actual thyroid hormones.  Those are the ones, especially, Free T3, that correlate with symptoms (energy, or lack of), where TSH does not.

Have you had a vitamin B-12 test?  As we age, we tend to absorb less vitamin B-12, which is very closely related to the amount of energy we have.  Ask your doctor to test that.  Any result under about 800 can produce symptoms of deficiency, even though the reference range might go all the way down to 200.

[tam1947]

THANKS
I'LL BE CALLING MY DOC IN THE MORNING
I assume all I need is a blood test for all of these answers?

[Barb135]

Yes, those are all blood tests.  Be sure to specify "Free" T3 and "Free" T4 and don't be surprised if your doctor doesn't want to order them.  Many doctors who, typically, only order TSH think the FT3 and FT4 are not necessary.  

TSH is a pituitary hormone, which neither causes, nor alleviates symptoms; one is only hyper (over medicated) if one has symptoms of hyperthyroidism, such as unexplained weight loss, diarrhea, hand tremors, mood swings, heart palpitations, rapid heart rate, anxiety, etc (but some of the those symptoms can also apply to hypothyroidism, which makes the FT levels that much more important).  

Many people who are hypo are also deficient in B-12, especially, as we get older.