She is 4 weeks late for her menstrual period. Physical exam shows a small goiter. A 76 year old woman presents with the new onset of atrial fibrillation. She has no history of heart disease. She has recently noticed increasing fatigue, but otherwise has no complaints.
Physical exam reveals a thin woman who is somewhat short of breath.
The pulse is irregular at a rate of 135 beats per minute. Hair and skin are thin. Eyes are normal. Reflexes have a normal return phase. She was a good student who had grown normally until the age of seven.