for me it started about 2 years ago. my job was 45 min away. i did everything to stay awake. slap my face, put the a/c on full blast, etc i was wondering if i might have chemical sensitivity disorder. i heard it causes fatigue. and with all of the pollution...there has to be quite a few chemicals out there. that is also when my pain got extremely worse. sitting in one position for such a long time. i was in sales and i had to drive most of the day selling ads for a newspaper. IT WAS NOT FUN!