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Incorrect Reference Ranges on Tests (Thyroid, iron, and more?)

Lotus97

Senior Member
Messages
2,041
Location
United States
I've been told by several people that the reference ranges on thyroid tests are wrong. Someone also said something about ranges of glucose might be wrong. Also, some my iron scores were in normal range, but others have said that it could be wrong. Is this a widespread issue and do I have to get a second opinion on all of my tests?
 

Plum

Senior Member
Messages
512
Location
UK
I don't know how things are in the US but in the UK ranges vary depending on the geographical area you get your tests done in. These ranges are often decades old and done on a sample population from the area!

I have been to 2 hospitals about 10 miles apart. At one my prolactin levels are 'normal' and at the other one the same test with almost the same result makes my levels 'high'. Why? Simply due to the 'normals' being different in the 2 areas.

If the normal ranges you're being given are way out I'd complain. I think wikipedia has some standard ranges you can check.

I've also learnt to look at results and take 25% off either end to view them from a functional perspective rather than a disease one - this can make things interesting.
 

Sushi

Moderation Resource Albuquerque
Messages
19,935
Location
Albuquerque
I just got thyroid tests back and they say after free T3:

Please note new reference ranges effective 11/06/2012

And after the TSH:

All TSH values represent 3rd generation TSH

So it looks like the ranges are regularly updated on some tests at least.

Sushi



 

Ema

Senior Member
Messages
4,729
Location
Midwest USA
I've been told by several people that the reference ranges on thyroid tests are wrong. Someone also said something about ranges of glucose might be wrong. Also, some my iron scores were in normal range, but others have said that it could be wrong. Is this a widespread issue and do I have to get a second opinion on all of my tests?
I'm not sure it is *wrong* so much as the ranges are just so overly wide that many times they need further parsing. Most of my doctors have developed optimal ranges instead which are much narrower.

For example, the range for fasting glucose goes up to about 100 usually but no functional medicine doctor would want to see your fasting glucose out of the 80s. That doesn't mean the range is wrong because if your result is in the high 90s you will still have gotten useful information that your sugar is getting too high and may be reflective of the development of pre-diabetes or metabolic syndrome.

"Normal" is not the same as "optimal".

Why don't you post your results and see what kind of feedback you get on the ranges? That might cut down the research burden to a more manageable level.

Ema
 

Lotus97

Senior Member
Messages
2,041
Location
United States
I've heard a few people say that free T3 should be in the upper third and TSH should be below 2.0 (my test's reference range for TSH is up to 4.78).

Ema
I was going to post my iron and thyroid results in a thread. Actually, it was a thread in which I was talking to you about those, but I sort of got bogged down with things and forgot. As I mentioned earlier in this thread though, my doctor has done over 30 tests so I can't post all of those in a thread. I suppose I could, but I try to make threads applicable to a larger number of people.
 

Ema

Senior Member
Messages
4,729
Location
Midwest USA
I've heard a few people say that free T3 should be in the upper third and TSH should be below 2.0 (my test's reference range for TSH is up to 4.78).

Ema
I was going to post my iron and thyroid results in a thread. Actually, it was a thread in which I was talking to you about those, but I sort of got bogged down with things and forgot. As I mentioned earlier in this thread though, my doctor has done over 30 tests so I can't post all of those in a thread. I suppose I could, but I try to make threads applicable to a larger number of people.
I think you can post whatever you feel comfortable posting. It's hard to know what someone else may or may not find applicable in the future and a discussion on reference ranges is always useful in my opinion.

I think that TSH non-medicated should be between 1-2 optimally. Once on thyroid medication, TSH is not always a good measure of thyroid function (even though doctors try really hard sometimes to justify its use). But I would say it is still best below 2 but may also be suppressed down to .2 or .3 without meaning that someone is hyperthyroid.

Non-medicated FT3 is generally in the top half. When on thyroid meds, it typically needs to be higher than that because there is more in the bloodstream as opposed to being converted on a cellular level as needed. So while on thyroid meds, an optimal FT3 is generally in the top third of the range instead.

Ema