Re: Time of TSH test - does it matter?
Originally Posted by kiya
Does it matter at what time of day you have a thyroid test done? It's just I've had two TSH tests done at different times of day and wonder whether this would make a difference in the levels recorded?
My first one was done at 8am in November and that recorded 2.17 (3.0-5.0) and the second one was done at 1pm early this month and recorded as 3.3 (0.4-4.0). Do TSH levels vary throughout the day as well as day to day?
TSH can vary by as much as 3 over the course of just one day and is USUALLY (though not always) highest late at night and drops steadily from that point onward, so yes. TSH varies throughout the day. The difference between the two TSH tests you had done are not statistically significant, though they are high enough that I would be investigating further, if I were your doc.
I am not a doctor, nor have I ever played one on TV...