Understanding test results

I was wondering if anyone could help me understand these results?

I had my TSH tested on three different occasions.  The results were:

1.19  uIU/mL

1.42  uIU/mL

1.25  mIU/L

What is the difference between mIU/L and uIU/mL?

[AR-10]

mIU/L stands for milli international units per liter.

uIU/mL stands for...I couldn't understand the explanation.
Sorry. Maybe I'll find it later.

[laura1967]

Too funny AR!!  You must have had a thyroid moment....lol
Quiltedhills- List the reference ranges with the results and see where you stand....I wouldn't worry about figuring out the difference.....just look at where you stand on the ranges. Also did you have a free t3 and free t4 done? You cannot get a complete picture without those. The tsh levels doesn't show the whole picture.

[AR-10]

Well...I couldn't figure out what they were saying!!
LOL!!

OK!

IU (mIU, uIU)
International Unit: An arbitrarily defined but agreed upon unit that depends on what is being measured.
mIU: 0.001 or one thousandth of an IU.
uIU: 0.000001 or one millionth of an IU.

Milliliter (mL)
0.001 or one thousandth of a liter.

So, it is two different ways of expressing the same measurement.

Thousandths of international units per liter, or Millionths of International units per one thousandth of a liter.

Same thing.

Good question, though. :o)

Slight variations in TSH from test to test can be expected. As Laura said, the Free T4 and Free T3 are more informative.

[quiltedhills]

Thanks!

My T4, Free was 1.13 (0.8 - 1.8)- so it was fine.

I don't think the T3 was tested unless it is disguised under the name of Thyroid Peroxidase- 40, but should be less than 35 or Thyroglobulin AB < 20 and needed to be less than 20.

I have a 3 cm nodule that tested fine from a FNA and was looked at again in October (6 months check-up).  I have developed two more nodules- 1 cm and smaller than one cm.  The endo will check them again in 6 months.

I was taken off of Synthroid 6 1/2 months ago, after being on it for 15 years.  I feel like I have some slight symptoms but nothing too bad- except, I think my hair has thinned some- but I don't know if it was from thyroid or not and I am watching it to make sure it does not get worse.  My doctor said I could go back on the medicine if I wanted but he does not think that I really need it.  I think I might get a second opinion so that I get a little more guidance.