Someday in last August, I woke up at 2am with irregular heart rate and was diagnosed afib. In the blood test, it shows Free T4 was 1.78 ng/dL (normal 0.89-1.70) , and TSH was 2.692 mUnit/L (normal 0.55-4.78).
I happened to have a blood test in the same hospital four days before the afib, and by that time, my Free T4 was 1.58 ng/dL, and TSH was 1.270 mUnit/L.
Any idea what could cause both Free T4 and TSH rise? Thanks!