Understand the evaluation of hypothyroidism.          

Explanation:

The two most important tests in evaluation of hypothyroidism are TSH and free T4 (total T4 may be almost equally good as free).

If a new patient has high TSH and symptoms of hypothyroidism- treat as hypothyroidism.If no symptoms-then check free T4. If free T4 is normal in such a new patient then the patient has what is called subclinical hypothyroidism and needs to be treated IF patient has goiter or thyroid antibodies or history of Radioactive iodine treatment in the past. These  predict the possibility of future development of hypothyroidism.

If the patient has had a pituitary ablation/surgery then use free T4 as the guide. If the patient is known to be on treatment  with thyroxin and has an elevated TSH but normal T4 then he has a compliance problem and usually forgets to take meds but popped in his dose just before coming to the doctor who checked the labs.