I have been on atenolol for 19 years. I think it effected my thyroid. I was on it for 7 yrs, was tired and cold all the time. Was put on thyroid medicine. I am still cold all the time, read on-line that atenolol slows down blood flow to hands and feet and can cause coldness. Also having hair loss and anxiety. It appears that the atenolol affected my thryoid, the thryoid medicine causes the anxiety - and the cycle continues!