Tsh .23 and free t3 and t4 in normal range. not taking any medication. the last time my tsh was done it was .17. can it make a difference on time of day test was taken? please help. surgeon is talking about removing my thyroid.?

What was the indication for thyroid function test? If this is just a routine check and you are asymptomatic then you should have a radioactive iodine uptake test to confirm hyperparathyroidism before proceeding to partial thyroidectomy. Time of blood test does not matter but taking a high dose of biotin may interfere with the result with certain test method. Good luck.