HYPOTHYROIDISM: Why does anyone ONLY check the TSH?


After staring down at the patient’s labs in front of her Tara, my nurse practitioner student(who is fantastic!) looked up at me and said, “So I’m confused, her TSH is normal but her Free T4 is low, so what are you supposed to do with this?” My reply was, “Well do we need to treat her hormone level or her stimulating hormone?” She answered, “Her hormone.” I said, “Good answer, we treat the T4 level.” She was then puzzled and asked, “So wait, then why does anyone ONLY check the TSH?” My reply was simple, “GREAT QUESTION.”

For those of you who read the above conversation and were thoroughly confused hopefully I can shed some light. Keep on reading.

The thyroid gland,which is located in our neck, produces two hormones, triiodothyronine  or T3 and thyroxine or T4, which control how the body uses and stores energy (aka metabolism).


Hypothyroidism is a condition where the thyroid gland does not produce enough thyroid hormone. This causes symptoms such as:

-lack of energy
-feeling cold all the time
-dry or coarse hair
-hair loss
-muscle spasms
-weight gain
-menstrual irregularities

There are many causes of hypothyroidism of which include surgery, medications, and even sometimes pregnancy. The most common cause of hypothyroidism is an autoimmune disorder called Hashimoto’s Thyroiditis. This is when your thyroid gland is attacked by your immune system which then destruct the thyroid tissue and therefore cause a decrease in the amount of hormone that is then released.

Hypothyroidism is diagnosed by symptoms and simple laboratory tests. And that is where we get into the importance of checking the entire thyroid picture instead of just one piece of the puzzle.

Most often patients have their TSH (Thyroid Stimulating Hormone) checked. In fact, most health care providers ONLY run a TSH and will call a patient back and tell him or her that their thyroid is normal. However, the TSH is measuring how well the brain is telling the thyroid gland to release hormone. It does not tell how much thyroid hormone is actually being produced and used throughout the body.

There are times that patients may have a normal TSH but have a low T4 or T3 hormone level. Therefore patients like this have hypothyroidism even though their TSH came back as normal.

All of this to say, if you truly think you have a thyroid problem please request that your health care provider check a full thyroid panel and not just the TSH. And if for some reason your health care provider won’t do this for you, then give our office a call. It’s our standard of care when we think we have someone that suffers from hypothryoidism. We want the full picture of what your thyroid gland is doing, not just a puzzle piece.

Finally, the symptoms of hypothyroidism can often mimic other physical problems so this post is not to say that if you feel tired that it means you have hypothyroidism. However, if you have any of the symptoms what do you have to lose to get your thyroid checked? If it is normal, then at least you know that it is not your problem.

As always, I hope you stay happy and healthy,

Carolyn Clark, NP-C