Hyposecretion of TH, Myxedema: Symptoms include low metabolic rate, thick and/or dry skin, puffy eyes, feeling chilled, constipation, edema, mental sluggishness, lethargy. If due to lack of iodine, a goiter may develop. Lack of iodine decreases TH levels, triggers increased TSH secretion, triggering thyroid to synthesize more and more unusable thyroglobulin. Thyroid enlarges