A tensed up vascular system drives higher blood pressure. This leads to prescriptions to lower BP. However, proper thyroid function promotes a relaxed vasculature and maybe a better place to start.

Part 3 Of A Series
This is a continuation of prescribing trends I have noticed in my pharmacy data from Island Drug / La Conner Drug. By-in-large it appears we are reaching for highly prescribed medications to treat symptoms of an underperforming thyroid, rather than support the thyroid itself. Please click here for Part 1 on cholesterol and/or Part 2 on Antidepressants.
Thyroid and Blood Pressure
We know the thyroid as an energy regulator. However, it goes much deeper. Besides the cholesterol component discussed in part 1, the thyroid affects the vasculature in consequential ways.
Systemic Vasculature Resistance (SVR)
Blood pressure readings include two numbers. For the textbook goal of 120/80, 120 is the systolic, 80 is the diastolic. Systolic is the force coming from the hearts pumping force. Diastolic is the pressure during relaxation. This diastolic component is an indicator of SVR. High diastolic, high SVR. Elevated SVR is a concern for everyone. We want a flexible vasculature, not one constantly rigid.
T3, the active thyroid hormone, produces artery relaxation and reduces SVR1. T3 also aids vascular integrity by inducing nitric oxide (NO) synthesis2. I wrote about NO in my detailed paper on cholesterol. NO is essential for cardiovascular health.
Hypothyroid and Hypertension
It is well established that diagnosed hypothyroid and hypertension go together. However, those with subclinical hypothyroid – blood levels of TSH still considered “normal”, are also at higher risk of hypertension.
A 2016 study looked at this and concluded that diastolic blood pressure is significantly higher in subclinical hypothyroid patients compared to normal3.
So, your “normal” but not optimal TSH value may lead you to a new blood pressure medication. This was the case in the prior two installations of this series.
Now, let’s look at some real data.
Prescribing Patterns
I expanded the same database from the other two articles to look at blood pressure medication vs thyroid prescribing trends.
Of the thousands of patients on blood pressure medications, 88% did not have a thyroid prescription on record.
On the flip side, 72% of the thyroid patients had no record of any blood pressure meds.
Powerful data to suggest that thyroid support helps avoid blood pressure prescriptions.
Thyroid Support
I spent several paragraphs on thyroid support in the thyroid/cholesterol article, click here for a direct link to these recommendations. Starting with gluten and fluoride avoidance, plus adding nutritional support can go a long way.
Take Away
Thyroid health is essential for cardiac health, we saw that in Part 1 on cholesterol. Here, mechanistically, low thyroid contributes to high blood pressure. Those who seek thyroid replacement avoid blood pressure medications, according to my data. Whereas a vast majority of BP Rx users have not used thyroid replacement.
If you have been told it is time to start a BP med, I think it prudent to request a thyroid blood test. However, the main test (TSH) has far too broad of a normal range. If you are in the upper end, say above 2, you could be in that subclinical range described above. Please reach out if I can help you through this evaluation.
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