... increased symptoms leading to your diagnosis of Hashimoto's? I quit smoking 9 months ago, two years prior I started having panic attacks, extreme fatigue, heart palpitations, weight gain (up and down) etc... I was also going through a nursing program and working full time while raising my three children as a single mom... I pretty much attributed these things to high stress levels although I am usually a highly energetic and optimistic person. I was having a hard time wrapping my head around the panic attack thing. When I quit smoking, I gained 40lbs in 4 months. I expected some weight gain but I was exercising and tracking my intake. I KNOW I was not consuming enough to gain like that. Then there was the fogginess, and even more extreme fatigue... I just knew something was not ok. after many trips to doc and the lab. I was diagnosed with Hashimoto's but prior to me quitting my levels were tested twice and were within normal range. ???