I was diagnosed with hashimoto's three years ago after going from one doctor to another complaining of being tired and being sick constantly. I was put on synthroid and made a big difference. In the last several months, i've begun getting tired again....Thinking that maybe it was time to increase the dosage. I went to the doc and he ran a blood test that showed my thyroid count was borderline low so he had me increase the synthroid by 25 mcg. Shortly thereafter, I began having heart palpitations and terrible headaches. I cut out caffeine and for a short time the heart palpitations/fluttering went away. But they resurfaced and I still have headaches. I went back to the doc to get retested. I also asked that he test for menopause. My lh was slightly elevated which indicated I was in "perimenopause" and my thyroid count was ok. But my thyroid seemed to have gotten bigger and I am very aware of my shirt collars being too close to my throat now...I feel like my clothes are strangling me. Any suggestions???? The heart problems really scare me.