I started talking about this on another thread but thought I should start my own to get other people's opinons on the matter.
In this thread healthunlocked.com/thyroidu... Clutter and Shaws posted a link to a very helpful page that explains that you should test as early as possible in the morning and that you shouldn't take your medication before the test but it also says that eating before a test can reduce your TSH.
This is the link thyroid.about.com/od/gettes...
A few days ago I had found the opposite suggestion on this site tiredthyroid.com/tsh.html It's a lot of reading so here's the bit that I am talking about which is sort of half way down the page
"TSH decreases when fasting. [17] Most patients do their lab tests in a fasting state, because other labs like glucose and cholesterol require it. But this may result in an artificially low TSH that does not reflect true thyroid levels. In fact, TSH has a circadian rhythm, with a peak around midnight (with much variability between individuals), and a low in the afternoon; fluctuations are normal. The change in TSH from peak to trough is approximately 72%. Free T3 levels also show a similar circadian rhythm (with a smaller amplitude) with a time lag of approximately 90 minutes behind the TSH curve. The Free T4 curve did not follow the TSH curve at all. [18] Labs drawn in the morning could be significantly different from labs drawn in the afternoon after lunch, with one TSH in "normal" range and the other in the hyperthyroid or hypothyroid range..."
So I'm really not sure which one to believe. I know that tsh is unreliable but unfortunately our doctors insist on using it as the tool to diagnose thyroid problems.
All I can go by is the two tsh tests I have had done
First one: 10.30ish am 1.4 FASTING
Second one : 9.10am 3.4 NOT FASTING
What are other people's experiences when having their tsh tests done?