> Slight [[hypothyroidism]] is a very common cause of chronic urinary infections. Both [[thyroid]] hormone and [[progesterone]] increase the (IgA) antibody production on membranes, improving resistance to infection, and they reduce the resistance to histamine, which tends to increase in the bladder under an excess of estrogen. Checking temperature and [[pulse]] rate in the morning and middle of the day is helpful as a first way to check for possible [[hypothyroidism]].