Why a standard thyroid test may be missing the problem
A few weeks ago, I shared how it’s not enough to just treat one gland when treating a hormonal imbalance, but instead all three (ovary, adrenal and thyroid) must be addressed. With that foundation, I wanted to jump into the thyroid in more detail.
The thyroid is a butterfly shaped gland that sits at the base of the neck. It responds to TSH (which comes from the brain) to produce T4 and T3. T4 is inactive and needs to be converted to T3, which is the active form of the hormone. Thyroid hormone has an effect on almost every tissue on the body, but the main effect is on metabolism. A properly working thyroid:
- Helps you feel energized
- Assures you’re burning calories in a balanced and efficient way (in other words, that extra bite won't go straight to your thighs)
- Keeps your body temperature balanced (goodbye cold hands and feet!)
- Your hair full and shiny
- Promotes normal and easy daily bowel movements
- Battles dry skin and brittle nails
- Contributes to normal cholesterol levels
Traditionally, the thyroid is evaluated looking at TSH. When thyroid levels are low, the brain gets the signal that production needs to increase and pumps out more TSH. Thus, higher TSH levels are correlated with lower thyroid function.
You may be thinking: I’ve had a thyroid lab and everything was normal.
Unfortunately, subclinical hypothyroidism is widely undiagnosed because the reference range for normal is so wide. Optimal TSH is considered between 1-2 and 2.5 being the top of the range. The conventional range flags above 5 which means that the thyroid is often quite decompensated by that point.
I think there are three key labs that need to be done in addition to TSH to get a complete look at what may be the underlying cause leading to thyroid dysfunction:
Check free T4 and free T3: Sometimes, the problem is not in the signaling between the brain (TSH) and thyroid, but rather in the thyroid producing enough T4 or converting to active T3. Free T4 and free T3 values help clarify at what point the thyroid is dysfunctioning.
Check antibodies: one of the leading causes of hypothyroidism (the fancy term for low thyroid) is Hashimoto’s which is an autoimmune condition. This means that the immune system is attacking itself and destroying thyroid cells, thus leading to lower function. The approach to treatment with Hashimoto’s differs from straight hypothyroid, so it’s important to know if they’re any antibodies present to proceed accordingly.
Check iron: many of the symptoms of low iron mimic low thyroid...fatigue, weakness, brain fog, low sex drive, and palpitations. One of the enzymes needed in thyroid production is dependent on iron, so making sure that your iron is adequate is important to know as well.
Figuring out how the thyroid is functioning and what may have gone awry (either straight hypothyroidism or autoimmunity) is an important step to getting your hormones to sync up for optimal health. A proper functioning thyroid can be the difference between tired, bloated and grumpy and energized, balanced and feeling good in your skin.
We’ll be riding the hormone train for a few more weeks, stopping next at adrenals then ovaries. Stay tuned!
All the best,