Hello. Thank you for your help. I am a 41yo woman with an excellent health history. I started running athletically last year, I am training for a marathon. I work in health care. Recently I ran a long course and afterward experience symptoms similar to those I had when diagnosed with a goiter and hyperthyroid problems at the begining of my last pregnancy: increased heart rate, fatigue, headache, light sensitivity, anxiety. I ran my own labs: TSH = 0.384, Free T4 = 1.17, Free T3 = 3.0, and Antithyroglobulin antibody = 131. My non-fasting triglycerides are at 44. My symptoms were bad for about ten days, then improved and I have been feeling mostly better the past week, but not great. I went for another long run today and felt O.K. but did not have nearly my normal level of energy. I wear a heart rate monitor to track my running statistics and was surprised to find when I got home that my heart rate for the last third of my run jumped suddenly to consistently over 200 (max 240) compared to my normal 140 or so. Again, I feel O.K. but not great and my heart rate is still a little high several hours later (85 vs. my normal 60-65).
I realize my labs are somewhat subclinical. I want to keep training. I am a breastfeeding mom. Would you advise me to seek treatment? Is it likely that I would be started on PTU? Should I just wait and repeat my TSH if my symptoms worsen? Will I cause muscle damage, or moreover, is it likely that I am endangering my health to continue training? I have been trying L-Carnitine and have been thinking that it perhaps helps somewhat with the headache. After my run today I am wondering whether I should be more concerned about my heart. I'm at a point in my life when I really don't want to have to slow down and stop running if I can avoid it. Thank you!