58-Year-Old Female Complains of Cold Intolerance and Weight Gain
Susan is 58 and presents to her primary care physician, complaining of cold intolerance and recent weight gain. She notes that she had been experiencing frequent hot flashes in the past. Now, however, she says that she can’t get warm.
Susan’s medical history is unremarkable except for her diagnosis of Stage III lung adenocarcinoma about a year ago. She reports that she is feeling better since her oncologist switched her to a new treatment. She pulled out a note pad with the word, durvalumab, and reported that this is her medicine.
Her PCP commenced with a physical exam. Her blood pressure was 120/85, with a slightly low heart rate of 58. Her CBC was within normal limits. Her blood chemistry profile was within limits; however, her thyroid-stimulating hormone (TSH) of 8.9 mIU/l, yet she had normal free thyroxine (fT4).
Why is it essential to distinguish between primary and secondary hypothyroidism?
How should this patient be managed?