Quick question...

[luke77]

Hey everyone,
I got my blood results back from my doc today...he said they were normal but didn't include the normal range. I looked the normal range up online and it appears to me that my thyroid level was not normal. These were my results:

TSH = 2.06
T4 = 0.59

On endocrineweb.com, it lists normal ranges as 4.6-12 ug/dl for T4 - so it seems like my T4 is WAY low. Am I missing something, or do some labs use different units or something? Also, I don't know much about thyroid - can anyone provide a link that talks about the link between hypogonadism and low thyroid (if there is one)?

Thanks very much,
Luke

 

[ASaxon]

I think you need to call either your doctor or the lab that did your blood work and get the reference ranges. There are no standard reference ranges for blood work as it all depends on the testing methods used by the lab. Perhaps T4 is more standardized than other tests but you really need the reference ranges. Once you get them then you can ask your doctor about your values.

Personally, I'd call the lab directly to get the reference ranges and then your doctor if you are low.

 

[luke77]

Thank you for the response, I will try to contact my doctor. I have a somewhat related question: with regards to total testosterone levels, I almost always see the reference range reported as about 300-1200 ng/dl. However, the reference range that my lab uses is 185-870 ng/dl. Is the difference in reference ranges due to a different process of analyzing the testosterone, or just because the lab that I go to has a different idea of what is "normal"? In other words, if my T level was at 400 at my lab, and the exact same blood was sent to another lab with the 300-1200 reference range, would it test as 400, or would it test higher? Sorry if this is a very simplistic question, but I was very surprised when I found out what my lab's T reference range was after reading stuff online.

Thanks again,
Luke

 

[SWALE]

The actual value will be proportionate within whatever reference range a particular lab uses.

 

[Douche_Nutz]

Luke, on one blood test that I had done, my local clinic's lab measured T4 like yours probably was. The range was something like .50-1.7 or something like that. Your range is probably similar. The normal range of 4.6-12 ug/dl for T4 is different, I think.

 

[ASaxon]

Reference Ranges.

As Swale pointed out, the reference ranges are proportional to each other. So if you had two blood samples sent to two different labs with different reference ranges and each test was accurately analyzed youd have proportionally similar results.

For example:

Total Testosterone from lab 1 might look like:
200 ng/dL with a Reference Range of 181 to 866 ng/dL

While the results from lab 2 might look like:
321 ng/dL with a Reference Range of 300 to 1080 ng/dL

Theyre the same results only different ranges.

There are other variables such as the fact that some labs use more refined age based reference ranges than others. You may also have to do some conversion from different units of measure (i.e. for instance from ng/dL to nmol/L).. I use the following websites for my conversions as I do not know all of the conversion formulas between the various units used in the medical profession..

http://www.statref.com/MedCalc3000/Basic.htm
http://www.get-back-on-track.com/en/tools/umrechner.php

From what I understand the Reference Ranges are based on statistical studies of populations of people of various categories (such as age, gender, etc.) against a particular testing methodology.

How they come up with the reference ranges is beyond me at this point. At first I thought it was a statistical analysis based on the 5th and 95th percentile values in a bell curve distribution, but now Im not so sure about that. I think whoever develops the reference ranges might push those values to where there are confirmed and documented illnesses in people. If they use this latter approach then reference ranges are largely subjective and completely depends on who determines who is ill or not, especially when it comes to hormones. If anyone has any ideas Id be interested in understanding this.

Anyhow, hope that helped in some way.

 

[LiquidGib]

As Swale pointed out, the reference ranges are proportional to each other. So if you had two blood samples sent to two different labs with different reference ranges and each test was accurately analyzed youd have proportionally similar results.

For example:

Total Testosterone from lab 1 might look like:
200 ng/dL with a Reference Range of 181 to 866 ng/dL

While the results from lab 2 might look like:
321 ng/dL with a Reference Range of 300 to 1080 ng/dL

Theyre the same results only different ranges.

There are other variables such as the fact that some labs use more refined age based reference ranges than others. You may also have to do some conversion from different units of measure (i.e. for instance from ng/dL to nmol/L).. I use the following websites for my conversions as I do not know all of the conversion formulas between the various units used in the medical profession..

http://www.statref.com/MedCalc3000/Basic.htm
http://www.get-back-on-track.com/en/tools/umrechner.php

From what I understand the Reference Ranges are based on statistical studies of populations of people of various categories (such as age, gender, etc.) against a particular testing methodology.

How they come up with the reference ranges is beyond me at this point. At first I thought it was a statistical analysis based on the 5th and 95th percentile values in a bell curve distribution, but now Im not so sure about that. I think whoever develops the reference ranges might push those values to where there are confirmed and documented illnesses in people. If they use this latter approach then reference ranges are largely subjective and completely depends on who determines who is ill or not, especially when it comes to hormones. If anyone has any ideas Id be interested in understanding this.

Anyhow, hope that helped in some way.

hey bro, i have been looking for a conversion tool, thx!

 

[SinginHawk]

Thyroid Values

You need more than the TSH and T4. You need T4 Free and Totak and T3 free and Total. They are more tell tale than TSH. Many doc don't even look at TSH.

Get those levels and ranges and that will giove you a good idea of where you are. Most doc like to see the levels at least at the median. That is take the range add the low to the high and devide by 2.

The T3 free is the active hormone. That is probably the most important.