I found an old blacks Medical dictionary in a second hand shop and looked up Thyroid (as you would) and was surprised to read . . .
"the weight of the thyroid gland is about 28.5 grams (1 ounce) but it is larger in females than in males, undergoes in many women A PERIODIC INCREASE AT EACH TIME OF MENSTRUATION, . . . "
Has any one Heard of this ?