Hyperthyroidism Support Group

Hyperthyroidism (or "overactive thyroid gland") is the clinical syndrome featuring weight loss (often accompanied by a ravenous appetite), fatigue, weakness, hyperactivity, irritability, apathy, depression, polyuria, and sweating. Additional symptoms may include palpitations and arrhythmias (notably atrial fibrillation), dyspnea, loss of libido, nausea, vomiting, and diarrhea.

0 Online

What's the difference between IU/mL and U/mL?

I didn't know where else to post and people here have been helpful in the past with interpreting lab results. My doctor doesn't know what to make me now (we tested other things this time, not just thyroid), and I'm on the waiting list to see some specialist for more tests.

My lab results show normal free T3, freeT4, and TSH. TSH is on the low end but it's been consistently hanging in there for a while.

My thyroid antibodies, however, appear to be off the charts and surely this must be a misprint.

The lab results from my _previous_ test showed:
TPOAb: 140 U/mL (normal range under 60)
TgAb: 86 U/mL (normal range under 60)

But my latest results show:
TPOAb: 245 IU/mL (normal range under 6)
TgAb: 35 IU/mL (normal range under 4)

I thought that perhaps there were zeros missing off the normal range, but both values were printed in red instead of black (by the lab) as being abnormal; which I reason the Thyroglobulin Ab wouldn't have been if it were 35/40.

I did go to a different lab. But I didn't expect the controls to be different and that confuses me. Other controls for TSH and fT4 were slightly different, but not by that much (TSH was 10-20 vs 9-10, and fT4 was 0.4-4 vs 0.3-5).

What is the difference between IU/mL and U/mL????
Does this really mean my TPOAb is 40 times higher than the normal range?



Maybe this chart may help you?


{{{hugs}}} :-)
Posts You May Be Interested In:
  • livingly

    Trouble sleeping

    hi has anyone with Graves' disease noticed that they have had trouble getting to sleep at night. I noticed I have. It's Like I'll feel tired and will be closing my eyes but I will still feel awake. Can anyone else relate
  • HyperSally

    PTU Dosage and Titrating

    Apologies for the long post. My question is at the top, history, details below.Question: I seem to be fairly responsive to PTU (got hive reaction to Tapazole after a month), but have been fiddling around with it and am on the brink of a hyper state. My TSH after making a climb to .27 has plunged back down to 0.01. and fT4s and fT3s are at the high point of the normal range. Any suggestions for a...