The thyroid is a small, butterfly-shaped organ, located in the front of the neck.
Your thyroid gland is managing your body’s metabolism. It produces 2 hormones that help maintain core body temperature and the production of amino acids and proteins:
the inactive thyroxine - T4 and the active triiodothyronine T3 (and a 3rd hormone called calcitonin which acts to reduce calcium levels in the blood that are released by your parathyroid hormone- PTH).
Let’s focus on T3 and T4 for this article though: when these 2 are out of balance, they can cause all sorts of health conditions including migraines or thyroid headaches (read more about symptoms, markers etc in this blogpost).
A recent study published in the Journal of Head and Face Pain found that people with pre-existing headache disorders - such as cluster or tension headaches - had a 21% higher risk of hypothyroidism. And people with a possible migraine disorder had a 41% greater risk.
The findings suggest that people with migraines are particularly susceptible to hypothyroidism. However, the study doesn't prove that one condition causes the other.
Past research has shown though that people who suffered from migraines in early childhood often developed hypothyroidism as an adult. And that once hypothyroidism has developed, migraines and headaches become more frequent and severe.
So we can agree that there seems to be a strong link between migraines and hypothyroidism.
If we look at how the thyroid works and consider other organs and glands that are impacted, it makes a lot of sense:
Brain function and thyroid function:
The brain (hypothalamus) is determining if more or less thyroid hormone needs to be produced and releases thyrotropin-releasing hormone, or TRH. TRH then stimulates the pituitary gland (also part of the brain) to release thyroid-stimulating hormone, or TSH. The thyroid gland makes thyroxine (inactive hormone T4) (with the help of iodine and tyrosine) and converts it (with the help of selenium) into triiodothyronine (active hormone T3). T3 and T4 are then released into the bloodstream and are transported throughout the body where they control metabolism, or the conversion of oxygen and calories to energy. So you can see that if your brain is inflamed, it also impacts your thyroid function.
Blood flow and thyroid function:
Thyroid hormones increase heart rate and promote vasodilation, which leads to enhanced blood flow to many organs. Thyroid hormones help your blood flow smoothly by relaxing the muscles of your blood vessels and keeping your blood vessels open. This can of course have an impact on your heart, but as we know, it can also create migraines or headaches.
Stress and thyroid function:
When stressed (mentally or physically), our body releases a hormone called Corticotropin-releasing hormone (CRH) that will trigger our adrenal glaproduce cortisol. CRH inhibits the production of TRH (thyroid hormone) and that in turn inhibits the production of TSH. So stress can lead to thyroid dysfunction.