I am 19 years old and I have just recently been diagnosed with an under active thyroid, and it has really affected my life. I am always tired and feel down and slow, and very moody and it has caused me to not be able to use the bathroom. Before this year I felt very healthy and energized, and very regular, but I find my self having horrible issues with my digestive system and had to go to the e.r. twice for those particular reasons.