Although I am under the care of an endo, I had to visit my GP recently for an unrelated problem for which she wanted to do a blood test. She also told me that, as I hadn't had a thyroid test for nearly a year, she'd do that too. This was at 10am after I had already taken that morning's T3 and last night's T4. I told her it would be pointless as I had already taken my meds and that the readings would be way off and she seemed to agree. Then a few days later I was phoned by the surgery to say that my bloodtests had come back with some anomalies and I should come in to see the GP. I did and she mentioned there was a problem with my thyroid test and before she could say any more I said: 'Let me tell you the result... TSH unreadable, T4 around 6.8 and FT3 around 8 or 9... right?' She confirmed the TSH and FT4 readings and that both were well below the lab ranges, but then told me they hadn't tested for FT3! Is this right??? I always assumed that they tested for TSH first and if that was abnormal, they would go on to test for FT4 and if that too was abnormal they would automatically go onto the next test which would be for FT3...
As I said before, the test results would have been completely irrelevant as I had taken all my meds that morning and the night before and, had I realised that she was still going ahead with the TFT I woulds have rebooked the test for a couple of days ahead so that I could at least have had a more true reading, but I was astonished to find that, in spite of my obviously abnormal results, the labs chose to ignore testing for the FT3.
TSH, FT3 & FT4 results
Labs in Western Sussex NHS instructed by CCG not to test FT4 unless TSH is out of range!
GP / lab won’t test FT4 !!
Low FT4 - below range
