Do any of these situations sound familiar:

• Do you feel tired all of the time?
• Do you have mental fog?
• Do you feel depressed?
• Are you constipated?
• Are you sensitive to temperature extremes?
• Is your hair falling out?

All of these are related to thyroid function.

The thyroid is a gland that sits at the base of our necks and controls the metabolic rate of our entire bodies. Thyroid hormones control how fast our cells work, how much work our cells do, and how many molecules of energy our cells produce. Without an optimally working thyroid gland, we feel sluggish and have trouble losing weight and even thinking. The body slows down. Every cell in the body, including those in the brain and the heart, need thyroid hormones to function properly. Low thyroid has been implicated in heart disease, especially congestive heart failure.

Basic Functioning of the Thyroid

As with all glands that produce hormones, the thyroid gland responds to feedback mechanisms throughout the body. The pituitary gland in the brain produces thyroid stimulating hormone, or TSH. TSH travels through the blood to stimulate the thyroid to produce thyroxine, or T4. T4 is not the active form of thyroid hormone; it is a protein with four iodine molecules attached to it. To convert it to T3, which is the active form of thyroid hormone, one of those iodines needs to be removed. This is done by every cell in the body, and different organs will convert T4 to T3 at different rates. (For example, the liver converts very quickly, but the heart does not.) T3 travels through the body to stimulate the metabolic rate of all of our cells. The conversion of T4 to T3 requires zinc, selenium, and iodine, so if you are low in these mineral, this conversion will be inadequate and you will not have enough T3 to feel energized.

T4 can also be converted to a molecule called Reverse T3. Reverse T3 is the mirror image of T3, and as such can bind to the T3 receptor sites. Instead of stimulating metabolism, reverse T3 prevents T3 from binding, which makes your entire metabolism slower. Reverse T3 is caused by stress, heavy metal toxicity, and an elevated serum insulin level. If you have a large quantity of reverse T3, your TSH can look good, but you may still feel like you have hypothyroid (characteristic of a slow thyroid).

The environment of the 21st century poses many threats to the thyroid gland. Thyroid glands are overtly affected by stress and toxins in our environment, such as heavy metals and bromide. Bromide is a chemical used in fabrics as a fire-retardant, and it displaces iodine in the thyroid which inhibits thyroid function.

Thyroid Treatment

Unlike general practitioners, anti-aging or functional medicine doctors are trained to recognize reverse T3. They will examine your level of stress. Cortisol, our stress hormone, greatly affects thyroid hormone production. Basically, our metabolism slows down when we are stressed.