I am a 19 year old woman with previously normal TSH levels. I get my blood work done every year, and every year the results have come back normal until now.
The first two tests were done by Quest Diagnostics for my primary physician, and the last two by LabCorp for my OB/GYN because he was diagnosing my irregular menstrual cycle. It turns out I may have Polycystic Ovarian Syndrome (PCOS), but I am otherwise very healthy.
July 19, 2008: TSH 0.63 mIU/L
May 02, 2009: TSH 0.73 mIU/L
July 21, 2009: TSH 0.014 uIU/mL
Aug 25, 2009: TSH <0.005 uIU/mL, Thyroxine (T4) 12.7 ug/dL, Triiodothyronine (T3) 215 ng/dL
The only symptoms I have that fit hyperthyroidism are intolerance to heat, excess sweating, and irregular period.
Why was my TSH level normal in May when I have always had these symptoms? And why is my TSH level dropping so rapidly now?