In general, hormones are molecules that signal the cells of the body to perform certain actions. A variety of hormones are produced in the various glands around the body; some of them affect many types of cells and others are more specialized.
The thyroid is a metabolic hormone, thyroxine (T4) and triiodothyronine (T3), secreted by the thyroid gland which regulates temperature, metabolism and cerebral function. Insufficient thyroid levels result in fatigue, increased cholesterol levels and increased risk of coronary artery disease. Low thyroid causes low energy, loss of motivation and thinning hair, skin and nails.
How it works!
After T4 and T3 are released by the thyroid, they hitch a ride in the bloodstream and get to work. They tell each cell if it needs to be consuming more oxygen and nutrients, thereby stepping up its rate of metabolism or vice versa. The hormones also have a hand in stimulating heart muscle contraction and nerve function, increasing the utilization of cholesterol and nutrients, ensuring normal growth and brain development.
When your thyroid’s not around to rev up your metabolism, a lot of things can go wrong. What’s scary is you usually don’t wake up one morning with every symptom on the list in full-fledged severity. You’ll just have a little more trouble making it through the day, or you may look in the mirror and see your face appears a bit puffy and more aged than it used to or you could get an ache in your muscles even after just walking a short distance. After a while, you’ll start to feel miserable all the time without even knowing why.
The thyroid hormone controls the speed of your metabolism. The pituitary gland (located in your brain) controls how much thyroid hormone to make. It does this by making thyroid stimulating hormone (TSH). TSH tells the thyroid gland to make more or less thyroid hormone. The thyroid hormone that is sent into your bloodstream is made from iodine absorbed from the foods we eat.