underactive thyroid
"This medication changed my life. I was diagnosed with subclinical hypothyroidism years ago and for five years I was on levothyroxine. Despite  taking it every day as recommended, I experienced no difference in my extreme fatigue, muscle aches, and constipation.  I was sleeping all the time. Exercise was a nightmare. No longer the energetic person I used to be. I basically wrote that off as my baseline. Then I started reading about different hypothyroidism treatments and beg my doctor to put me on Naturthroid. I now feel exactly how I am meant to - boundless energy  when I get up in the morning at all throughout the day, and as a result, my mood has dramatically improved."