The thyroid gland is the main energy center of our body. It regulates the metabolic rate, body temperature, heart rate, and the overall level of our vital energy. When a person experiences chronic fatigue, apathy, weight gain, foggy head, and hair loss, doctors most often refer them to check thyroid hormones (TSH, T3, T4). And very often they detect hypothyroidism (decreased gland function) or autoimmune thyroiditis (AIT).