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Maryland21229 06-18-2005 06:24 PM

What is difference between TSH and TSH Cascade?

My TSH is 2.641 and TSH Cascade is 2.646. That was the only thyroid blood test run and I was told it is in the normal range (0.350-5.500). Yet on this board, I read that it is not. I live in USA.

Am being evaluated for potential thyroid prob. Hair started falling out, also racing heart among other things. Am waiting for all test results from dr., but this is what I know so far:

1. US showed 2 nodules on the left lobe that are definitely not cysts.
2. RAIU at 3 hrs. was 7.7%, at 24 hrs. was 23% (is this normal?)

Is it normal to have one side of the thyroid be much smaller than the other?

There is nerve pain in the neck that radiates from left side of Adam's Apple up to salivary glands under ears, and a vague feeling of upper chest compression.

All blood tests, including FSH and LH are where they should be at my age. Dr. does not think my symptoms are due to menopause. So what are the thyroid possibilities here?


SadFreek 06-19-2005 03:55 AM

Re: What is difference between TSH and TSH Cascade?
how long were you up when the blood was taken? How many hours?

Maryland21229 06-19-2005 07:40 AM

Re: What is difference between TSH and TSH Cascade?
In response to SadFreek I had blood drawn for the TSH Cascade at approx. noon and had been up since about 6 a.m. So about 6 hrs. Does that make a difference?

midwest1 06-19-2005 10:37 AM

Re: What is difference between TSH and TSH Cascade?
The thyroid possibilities are large.
I can't comment much on the nodules and physical findings, although no one can say it's ever "normal" to have one lobe much larger or smaller than the other.

As for "TSH cascade"... It's a method of testing with a "cascade" effect. That is, if the first test performed - the TSH - is abnormal, it is only then followed up with FT4. If that's abnormal, it then is followed with more tests. The likelihood of finding a thyroid problem hinges on the TSH... which often is [i]interpreted[/i] as normal when it actually isn't. Because TSH by itself is never conclusive if symptoms are present. I'm not a fan of this style of test. "TSH with reflex to FT4" is another such method.

The National Academy of Clinical Biochemistry most recently suggests that a sustained TSH above 2.5 probably isn't normal for anyone, and that a trial of supplemental hormone is called for in those cases if symptoms are present. The physical difficulties your gland has suggests it may be struggling to keep up with your hormone needs.

SadFreek 06-19-2005 02:25 PM

Re: What is difference between TSH and TSH Cascade?
If you'd been up for 6 hours, your TSH is prolly like 6+ as you first get up. the TSH drops throughout the day.

my TSH after being up for about 30 minutes was 4.565. After being up for about 4 hours, it was 2.61. About 6 hours, it was 1.91.

I would suggest you have your blood taken as soon as you get up in the morning as your TSH is at its maximum.

I was recently diagnosed hypo last week. Based on TSH alone.

Good luck and I hope that your doctor isn't an idiot like 99% of them. (I went through 4, and I was lucky then!)

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