The thyroid is a small, butterfly-shaped gland that is an indispensable aspect of the bodys hormonal system. Weighing less than one ounce the thyroid is located in the front of the neck.
The thyroid is the bodys gas pedal. Every aspect and process in the body is dependent on and affected by the thyroid.
When the thyroid is overactive (hyperthyroidism) and producing too much thyroid hormone, or if the person is taking in too much thyroid, metabolism speeds up. The heart rate may speed up; the person may experience anxiety, weight loss, bowel problems, difficulties with concentration or other problems.
In the event that the thyroid is under active, or hypothyroidism, a person will often experience fatigue, intolerance to cold, constipation, hair loss, weight gain and puffiness. A person with hypothyroidism may often go to their doctor complaining that various parts of their system are just not working well. They may just feel lousy; women may complain that their menstrual cycle is disrupted or that they are having problems getting pregnant. Men and women may complain of low libido or weakness.
Thyroid hormone is produced in the thyroid by the addition of iodine to an amino acid called tyrosine. Interestingly, thyroid cells are the only cells in the body, which can absorb iodine. When iodine is deficient in the body during infancy and the thyroid does not develop correctly, it can have devastating effects on the child. The thyroid gland produces primarily thyroxine (T4), which is then converted in the body to tri-iodothyronine (T3), which is really the active aspect of thyroid in the body.
The thyroid gland is under control of the hypothalamus and pituitary gland of the brain, and a feedback loop is created whereby the amount of thyroid in the body feeds back on the thyroid to tell it to slow down or speed up in the production of hormone.
There are many reasons why the thyroid can become over or under active. The most common are autoimmune problems, where the body literally attacks itself. This is often genetically related and can be common in families. Examples are Hashimotos Thyroiditis and Graves Disease. Other problems that affect the thyroid include viral infections, radiation and iodine deficiency.
Diagnosing the thyroid problem can at times be difficult. The best way to find a hidden problem is to check the thyroid stimulating hormone level, free T3 and T4 levels, and thyroid antibodies.
Diagnosing thyroid problems is usually the easy part. Once the thyroid problem is uncovered treatment is often straight forward and generally synthetic T4 (called Synthroid) is used. However there are some people who do not on their own convert T4 to T3 well and seem to do better when treated with a combination of T4 and T3. Some do best with T3 by itself. This must be individualized carefully and closely monitored by the treating physician.