Your thyroid gland is a small, butterfly-shaped endocrine gland located in the base of the neck just below the Adam’s apple. Although relatively small, the thyroid gland plays a huge role in our body. It influences the body’s metabolism and regulates the function of the body’s most important organs, including the heart, brain, liver, kidneys and skin.
Think of your thyroid as a car engine that sets the pace at which your body operates. An engine produces the required amount of energy for a car to move at a certain speed. In the same way, your thyroid gland manufactures enough thyroid hormone to prompt your cells to perform a function at a certain rate.
Just as a car can’t produce energy without gas, your thyroid needs fuel to produce thyroid hormone. The thyroid’s main fuel is iodine. Iodine comes from your diet and can be found in iodized table salt, seafood, dairy products, beans, nuts and greens. Your thyroid extracts this necessary ingredient from your bloodstream and uses it to make two kinds of thyroid hormone: 1. Thyroxine, also called T4 because it contains four iodine atoms, and 2. Triiodothyronine, or T3, which contains three iodine atoms. T3 is made from T4 when one atom is removed, a conversion that occurs mostly outside the thyroid in organs and tissues where T3 is used the most, such as the liver, the kidneys and the brain.
Once T4 is produced, it is stored within the thyroid’s vast number of microscopic follicles. Some T3 is also produced and stored in the thyroid. When your body needs thyroid hormone, it is secreted into your bloodstream in quantities set to meet the metabolic needs of your cells. The hormone easily slips into the cells in need and attaches to special receptors located in the cells’ nuclei.
Your car engine produces energy, but you tell it how fast to go by stepping on the accelerator. The thyroid also needs some direction; it gets this from your pituitary gland, which is located at the base of your brain. No larger than a pea, the pituitary gland is sometimes known as the “master gland” because it controls the functions of the thyroid and the other glands that make up the endocrine system. Your pituitary gland sends messages to your thyroid gland, telling it how much thyroid hormone to make. These messages come in the form of thyroid-stimulating hormone (TSH).
TSH levels in your bloodstream rise or fall depending on whether enough thyroid hormone is produced to meet your body’s needs. Higher levels of TSH prompt the thyroid to produce more thyroid hormone. Conversely, low TSH levels signal the thyroid to slow down production.
The pituitary gland gets its information in several ways. It is able to read and respond directly to the amounts of T4 circulating in the blood, but it also responds to the hypothalamus, which is a section of the brain that releases its own hormone, thyrotropin-releasing hormone (TRH). TRH stimulates TSH production in the pituitary gland. This network of communication between the hypothalamus, the pituitary gland, and the thyroid gland is referred to as the hypothalamic-pituitary-thyroid axis (HPT axis).
What Happens When Things Go Wrong
The HPT axis is a highly efficient network of communication and normally the thyroid doles out just the right amount of hormone to keep your body running smoothly. TSH levels remain fairly constant, yet they respond to the slightest changes in T4 levels and vice versa. But even the best networks are subject to interference.
When outside influences such as disease, damage to the thyroid or certain medicines break down communication, your thyroid might not produce enough hormone. This would slow down all of your body’s functions, a condition known as hypothyroidism or underactive thyroid. Your thyroid could also produce too much hormone sending your systems into overdrive, a condition known as hyperthyroidism or overactive thyroid. These two conditions are most often features of an underlying thyroid disease.
Out of Gas
Sometimes the thyroid can’t meet your body’s demands for thyroid hormone, even though TSH levels increase. As your body slows down, you may feel cold, tired and even depressed. You may gain weight, even though you’re eating less.
There could be a number of reasons why your thyroid is not performing well. For example, if your body isn’t getting enough iodine, your thyroid can’t make enough thyroid hormone, but it will try to respond to rising TSH levels by working harder and harder anyway. This can cause your thyroid to become enlarged and develop into a goiter that looks like a protrusion or large swelling in your neck. Goiters used to be common, but they have become much less common in developed countries because of iodine-fortified foods. But even with these fortified foods, most people are iodine deficient.
In other cases, your thyroid comes under attack by your body’s own immune system. Normally, substances called antibodies protect you from dangerous bacteria and viruses. But in this condition, known as Hashimoto’s thyroiditis, your antibodies mistake your thyroid for a foreign invader.
All Revved Up
Sometimes your thyroid keeps churning out more thyroid hormone, even when your pituitary gland completely shuts down TSH production, a clear signal that your body has had enough. Yet the thyroid appears oblivious to the lack of signals and continues to produce too much, pushing your metabolism into overdrive and speeding up your body’s processes. This condition is called hyperthyroidism.
If you’re hyperthyroid, your pulse may be racing, you feel irritable and overheated, and you have trouble sleeping. You may lose weight in spite of a good appetite and experience anxiety and nervousness. As with hypothyroidism, you may develop a goiter; in this case, your thyroid enlarges because your thyroid is working so hard overproducing thyroid hormone.
Graves’ disease, an autoimmune disease that is the most common cause of hyperthyroidism in the United States. As with Hashimoto’s thyroiditis, antibodies attack the thyroid, but in this case, they stimulate the thyroid to overproduce thyroid hormone.
So to review, there are three main types of thyroid conditions and their symptoms:
- Hypothyroidism (underactive thyroid). With hypothyroidism you will feel tired, weight gain, feeling cold even in the summer, muscle weakness and aches in your joints, unusual hair loss, itchy, dry skin, depression or the blues, inability to concentrate or remember, and chronic constipation.
- Hyperthyroid (when it overworks and can burn out). With hyperthyroidism you will have symptoms of nervousness and anxiety, a fast or irregular heartbeat, fatigue due to inability to rest or sleep, mood swings, weight loss, insomnia, inability to relax, hand tremors and muscle weakness and increased urination and bowel movements.
- Autoimmune diseases (like Hashimoto’s or Graves disease) With these types of thyroid issues, you may develop a goiter, experience weight gain, have fatigue, puffiness of the face, have joint and muscle pain, thinning of your hair, depression and slowed heart rate.
As you can see, a lot of the symptoms of thyroid disease overlap. The only way to determine if you have a thyroid issue is to do a blood test. Most doctors only test for TSH, but that is only part of the story. A complete thyroid blood test or a Complete Thyroid Panel will not only measure the TSH level, but will also check the levels of Free T4, Free T3, Reverse T3, T3 Uptake and if need be, Thyroid Antibodies.
If your results come back positive for one the three types of thyroid conditions above, we can proceed to not only change your diet, but recommend natural supplements to aid the thyroid in its recovery.
To schedule your blood test today, call Doctor’s Nutrition at