About 20 years ago I was put on synthroid (100 mcg) daily. At the time, I probably weighed around 170 lbs. My dose has never been changed through the years. I now weigh about 128 lbs. I have also been taking Tegretol for 30 years (until recently when was took completely away- now take Keppra instead). I rock back & forth 24 hrs a day- my heart races and pounds loud in my head- especially when getting up and down from laying. Have less frequent periods & lighter. Can't stay asleep. Can go to sleep--- but wake up 8- 10 times a night. I haven't had a blood test from my 'regular' doctor that prescribes the thyroid medicine since last summer (2011) . Will call tomorrow to 'demand' thyroid function test. Any ideas ???