Question 1

low tsh high free t4?  what is the cause?

Accepted Answer

Hyperthyroidism: High ft4 and low TSH are a combination usually indicating an over active thyroid. It doesn't explain the cause which will require further testing to figure out.

Question 2

cause of constant low t4 free, but normal t4, t3 (liothyronine) and tsh?

Accepted Answer

Level of TBG: All laboratory results need to be interpreted in the clinical context and the doctor who ordered the tests is usually in the best position to do that. Having said that, if you have high level of thyroglobulin binding protein (TBG) that will make your total T4 high when free T4 may be low. However, if your TSH is in the normal range, you are not likely to be thyroid deficient.

Question 3

can low tsh alone cause hyperthyroidism symptoms or would t3 and free t4 have to be abnormal too?

Accepted Answer

: All laboratory results need to be interpreted in the clinical context and the doctor who ordered the tests is usually in the best position to do that. Talk to the doctor who ordered the tests. Having said that, it is the elevated free T3 which is the molecule mediating the effects of thyroid function.    
Wish you good health!

Question 4

normal range tsh and free t3 but low t4?? just had my thyroid labs done - tsh - 1.88, free t3 - 3.3 and free t4 is .87. what would cause this? i dont sleep great with my 2yo waking up every night but why is t4 low? is t3 high?is this a bad balance?

Accepted Answer

: The Dr who ordered these tests knows your entire history and any current symptoms. They are the best resource for reading these labs in the correct context of your full medical history/exam/other labs. It would not be appropriate for a Dr online to try and determine a diagnosis based on two lines of information.

Question 5

i have normal hearth functions and tests. would arrhythmias caused by high free t4 stops once levels go back to normal?

Accepted Answer

: Should if due to high free T4

Question 6

what is meant by low tsh high free t4?

Accepted Answer

Hyperthyroidism: A low TSH and high T4 is an indication of over-active thyroid (hyperthyroidism). This should be evaluated further for any potential cause and discuss treatment options with your physician. Referral to an endocrinologist may be necessary.

Question 7

my tsh levels are normal, but my free t4 is low...hypothyroidism?

Accepted Answer

Pituitary evaluation: If the TSH is normal, it means that you do not have primary hypothyroidism.  However, you could still have secondary hypothyroidism because of a pituitary problem.  You should see an endocrinologist for further evaluation.

Question 8

my tsh was 3.18 but my free t4 was a 1.8 which was high. will the high free t4 cause any problems?

Accepted Answer

Cannot diagnose: You need a full assessment correlating your lab values with clinical symptoms. Taking the numbers alone is not appropriate for any purpose, but elevated thyroid hormone levels can suggest hyperthyroidism. You must discuss this with the doctor who ordered these tests. Good luck.

Question 9

hello, i just received labs results for tsh at 0.0236 low and tsh rfx on abnormal to free t4 at 1.78 high should i be concerned i am dx hypo?

Accepted Answer

Clarify question: If you are being treated for hypothyroidism-the dose has to be reduced.
Consult an endocrinologist.

Question 10

i am on 100mcg of synthryoid. my test results are tsh 0.324, free t4 is 1.3, free t 3 is 2.410 should i be lowered i am experiencing, low fevers, inne?

Accepted Answer

Need Eval: Goal TSH for people with hypothyroidism is 0.3 to 3 IU/mL your T4 is mid nl &amp; free T3 on the low end of nl. It is unlikely, the fevers are from the thyroid. You should repeat them, but take your Synthroid (thyroxine) after the labs that day. Also, when ill the TSH &amp; free T3 can decrease, something called euthyroid sick syndrome &amp; gen wouldn't check while ill. The cause of fevers also cause the abnormal labs.

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Doctor answers about:

Causes low free t4

A member asked:

Low tsh high free t4? what is the cause?

A member asked:

Cause of constant low t4 free, but normal t4, t3 (liothyronine) and tsh?

A member asked:

Can low tsh alone cause hyperthyroidism symptoms or would t3 and free t4 have to be abnormal too?

A member asked:

Normal range tsh and free t3 but low t4?? just had my thyroid labs done - tsh - 1.88, free t3 - 3.3 and free t4 is .87. what would cause this? i dont sleep great with my 2yo waking up every night but why is t4 low? is t3 high?is this a bad balance?

A member asked:

I have normal hearth functions and tests. would arrhythmias caused by high free t4 stops once levels go back to normal?

A member asked:

What is meant by low tsh high free t4?

A member asked:

My tsh levels are normal, but my free t4 is low...hypothyroidism?

A member asked:

My tsh was 3.18 but my free t4 was a 1.8 which was high. will the high free t4 cause any problems?

A member asked:

Hello, i just received labs results for tsh at 0.0236 low and tsh rfx on abnormal to free t4 at 1.78 high should i be concerned i am dx hypo?

A member asked:

I am on 100mcg of synthryoid. my test results are tsh 0.324, free t4 is 1.3, free t 3 is 2.410 should i be lowered i am experiencing, low fevers, inne?

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