Understanding a TSH Reading

When I first was getting blood drawn for thyroid tests, I was really confused by the readings. My TSH would be HIGH but I would be HYPOthyroid (under active thyroid). It just seemed backwards and confusing to me.


I spoke with my doctor and I did a little research. TSH is the Thyroid Stimulating Hormone produced by the pituitary gland. When your thyroid is not working enough the pituitary glands produces more TSH in hopes of stimulating your sluggish thyroid. Thus, if your body thinks your thyroid is not working well, the brain will tell the pituitary gland to make more TSH. So, when you read your thyroid labs a high TSH could mean hypothyroidism, and a low TSH could mean hyperthyroidism (hyper because your body is not needing more thyroid so the pituitary is producing less TSH).


I have mentioned previously that my doctor is keeping me a little hyperthyroid to suppress any growth of thyroid cells in my body (to prevent more cancer). My optimal TSH level for the first five years after having cancer is between .05 and .5. That's pretty low, and I definitely feel some hyperthyroid affects because of it. In contrast, my guest poster's TSH was 8.0 when she was first checked. That's super high, and she was most definitely hypothyroid.


The optimal TSH level can be anywhere between .5 and 5.0. (source).


***This post is part of a series I am doing because it's Thyroid Health Awareness Month. I am not a physician, nurse, or anything like that. I am a woman who's had to learn a lot about her thyroid in the past year. My almost-lawyer-husband would be so proud that I'm including the following:  I am not liable for this information nor for the decisions you make based upon what I post. My hope is to teach people some basic thyroid information but if you have real concerns talk to your doctor!***