Why A TSH Level Isn’t Enough To Understand Your Thyroid Condition

Why a TSH level isn't enough to understand your thyroid condition

In mainstream medicine, TSH is considered the gold standard for the diagnosis and treatment of thyroid disease. The sad truth is that this one lab test FAILS to give a full picture of thyroid health and leaves many thyroid sufferers undiagnosed or insufficiently treated. Thyroid health is a puzzle with many important pieces.

Written by Candace J. Burch, MA

As women, we’ve all had times when we feel invincible. Like we can hit all of our marks and land on our feet every time.

And then there are times when we don’t. When the wind comes out of the sails. When the grease is missing from the wheels.

Hopefully these times are temporary . . . but sometimes they linger. And when they linger too long, we start to worry that something in our beautiful machinery may have gone awry.

First, we think about the easy fixes – Could it be too much junk food? Could it be that time of the month? Could it be too much stress at work or home?

As weeks drag into months, we know it’s something bigger. And those who dig deeper find that persistent symptoms of feeling cold, sluggish and depressed can indicate a thyroid issue. Seeking answers, our doctors run a thyroid test and many times the results come back “normal.”

Normal? How Can This Be?

“The way I feel cannot be called normal.”

Given that many symptoms of low thyroid overlap with symptoms of other conditions – i.e., constipation, aches and pains, depression, fatigue, etc. – we need to know to look deeper. And we may not get the answers we need unless we find a provider who goes beyond the standard TSH test to address thyroid disorders in the greater context of hormone imbalance.

Typically, when low thyroid function is suspected, doctors will take a blood draw to measure TSH levels. TSH, or thyroid-stimulating hormone, is a hormone secreted by the pituitary gland that then stimulates the thyroid to produce thyroxine (T4). Knowing that you’re making the right amount of TSH is important, but this test only tells part of the story.

The Tests Your Doctor Should be Doing

It may surprise you to know that our bodies produce more than one thyroid hormone.

In fact, there are two hormones you need to know about – thyroxine, the T4 mentioned above, and triiodothyroinine, or T3.

T4 is the most abundant thyroid hormone; and its job is to convert to T3, which is the most active thyroid hormone in the body. We need our body to make adequate levels of these two hormones, as we rely heavily on them for an active metabolism and regulation of body temperature.

The efficient conversion of T4 to T3 has to occur in order for your body to have healthy thyroid function. So, anything that interferes with that crucial conversion process will decrease thyroid function, slow metabolism and trigger a rush of low thyroid symptoms. A normal T4 level with a low T3 level indicates poor conversion, even though thyroid hormone production by the gland itself is normal. (This is one of the main reasons it’s essential to test more than just TSH!)

TPO, or thyroid peroxidase antibodies, is one other important piece to the puzzle. TPO is an enzyme expressed mainly in the thyroid that assists in the chemical reaction that produces T4 and T3. In an autoimmune disorder known as Hashimoto’s disease, the body produces TPO antibodies that attack the thyroid gland resulting in thyroid symptoms, so high levels of these antibodies are used to diagnose this condition and indicate the extent of the disease.

Make sure to address these important values when discussing thyroid testing with your provider. If all of these tests are not included, you may not be getting all of the information that you need.

Think About More than Just Thyroid

If these specific thyroid tests don’t give you all of the information you need about your thyroid function, there are other avenues for you to consider.

From hormone imbalances to mineral deficiencies, a variety of other factors can interfere with thyroids’ crucial conversions.

Here are a few of the most likely culprits:

  • Elevated cortisol stress hormones – Cortisol is known as the master stress hormone, and we need it to survive. But, when in excess, cortisol can interfere with the conversion of T4 to T3. Likewise, cortisol that is too low can also be problematic for thyroid function.
  • Iodine deficiency – Iodine is essential for the production of thyroid hormone, and the body doesn’t make it – so we need to get it from our diets. The good news is that iodine is already in foods that we regularly eat like yogurt, milk and eggs. It’s also found in ocean fish and shellfish, as well as seaweed and iodized salt.
  • Selenium deficiency – Enzyme conversion to active thyroid hormone levels depends on adequate selenium and iodine levels (see above). People with low protein diets or those living in areas where the soil is mineral depleted (the so-called Goiter Belt of the Midwest) often have deficiencies that undermine conversion, causing symptoms of hypothyroid. Supplementing with selenium and/or eating food sources such as brazil nuts, seafood, eggs and grains can help turn things around.
  • High estrogen – Thyroid problems are more prevalent in women, and one of the reasons is that excess estrogen can be a player in low thyroid function. High levels of estrogen induce over-production of the thyroid-binding globulin that binds up active thyroid hormones, making them less available for the body to use. This is most often seen in women who are taking estrogen – like the pill or hormone replacement therapy.

Taking action to make sure we’re getting the right testing to identify the root cause of our health issues is the first step on the path to feeling our best.

About Candace Burch, MA

Candace J. Burch, M.A., is a writer, speaker and Hormone Health Educator for ZRT Laboratory. She has been a woman’s health advocate and champion of natural approaches to hormonal health for over 25 years. She received her Master’s degree in Health Education and has worked in the health industry since 1979. She is a founding member of Women in Balance, a non-profit dedicated to helping women in perimenopause and menopause find safe solutions for symptom relief and natural hormone balancing.


Take Back Your Thyroid Health! Sign up and never miss a post - it's FREE

Thank you. I appreciate every share on social media!

About Dana Trentini

Dana Trentini founded Hypothyroid Mom October 2012 in memory of the unborn baby she lost to hypothyroidism. This is for informational purposes only and should not be considered a substitute for consulting your physician regarding medical advice pertaining to your health. Hypothyroid Mom includes affiliate links including the Amazon Services LLC Associates Program.


  1. Linda Mason says

    Hello…I finally got the PA at my doctor to listen to me. My labs were TSH 1.520, T4 6.6, T3 64 (low). Had been experiencing depression, anxiety only in evening, extremely dry, scaly legs and forearms, lethargy only after arising in the morning for a couple of hours, fog brain, and some weight gain without change in diet. I requested a trial of cytomel 5 to see it it would help. I cut in half and took 2.5 twice daily. Within 5 days I felt considerably better. After 6 weeks, labs showed TSH0.819, T4 4.8, T3 72 (just one point above low normal). Was told to start cytomel 5 once in a.m. and not split dose anymore. A few weeks later, I started to feel a little sluggishness in the afternoon and a slight feeling of anxiety in the evening. I feel I need 2.5 cytomel in the afternoon as I think my body has adjusted to the 5 cytomel. I was told since my TSH was0.819 my Dr. Was concerned about a thyroid storm if she increased the cytomel in the afternoon. What is a thyroid storm??? if only increased by 2.5, it does not seem unreasonable since my T3 was barely above low normal. Please tell me your opinion…it’s so difficult to get doctors to listen about thyroid….I don’t get it! Thank you!

Speak Your Mind