I recently held a class about the thyroid and realized sharing this information might help more people find the cause of their hypothyroid symptoms and resolve them more quickly.
In a healthy thyroid, the thyroid mostly makes a hormone called T4. T4 converts to T3, the most potent, active thyroid hormone. When someone is under stress, the body will often convert T4 to Reverse T3 (RT3). RT3 is an inactive substitute for T3. When RT3 levels are high, we know stress is the cause for hypothyroid symptoms which requires temporary treatment to resolve. Here is a brief schematic to help simplify.
Normal function T4 ——> T3 (active hormone)
Under stress T4 ——> RT3 (inactive hormone, leading to hypothyroid symptoms)
There are many symptoms of hypothyroidism, some include fatigue, hair loss, weight gain, depression, brittle nails, insomnia, headaches, high cholesterol, acne, allergies and even carpal tunnel syndrome.
Lab testing for the thyroid often includes T4, sometimes T3 but rarely RT3. Having all 3 lab tests done can reveal the cause of symptoms and direct the physician to use a temporary treatment of supplements or T3 that may resolve the issue without long-term use of medication.