The thyroid gland is a small gland that sits in the neck of humans and some animals. It is part of the larger endocrine system, and its main job is to secrete a unique thyroid hormone that helps the body do a range of different things, from managing temperature to processing energy from food. Keeping these hormones at balanced, regular levels is very important to overall health. The gland is typically quite small, but problems with the way it works can be very serious. People with persistent thyroid problems often take synthetic versions of thyroid hormone in order to keep their bodies functioning optimally, and a number of regulatory drugs are available depending on the specifics of the issue and the patient.
Location and Identification
This gland is the most visible and certainly the largest part of the endocrine system in humans, and in most animals, too. Broadly speaking, the endocrine system is what keeps hormones balanced and regulated. Hormones are internal chemicals that can trigger all sorts of things, from emotions to sensations organ functioning and metabolic efficiency.
The thyroid gland is located in the front part of the neck, just below the Adam's apple. People can’t usually feel or see it from the outside, in part because of how tightly it “hugs” or wraps around the trachea. It is butterfly-shaped, with "wings" known generally as the left and right thyroid lobes. In most cases the gland protects a number of nerves and muscle tissues by virtue of its shape and location.
Main Function
In healthy people, this gland functions in cooperation with the hypothalamus and the pituitary gland. The hypothalamus sends a signal to the pituitary gland through a hormone called the thyrotropin releasing hormone (TRH), and the pituitary gland then releases thyroid stimulating hormone (TSH) to the thyroid gland. Next, the thyroid releases T4 and T3 hormones, which enter the bloodstream and affect the metabolism of the heart, liver, muscle and other organs. The pituitary gland regulates the level of thyroid hormone in the blood and increases or decreases the amount of TSH released.
Hormone secretion is usually understood to be the thyroid’s primary responsibility. When thyroid hormones are imbalanced or out of synch, people are prone to experience a number of health concerns. Tracing problems back to the thyroid can be difficult without medical scans and tests for the presence of thyroid hormone, though issues are common enough that health care professionals in many parts of the world are specially trained in looking out for the signs and often run hormone screens as a matter of course when problems are suspected.
Hormone Regulatory Problems
Hypothyroidism, also known as “underactive thyroid,” is one of the most common thyroid gland problems, and it occurs when the thyroid fails to produce enough hormones. This disorder can often go unnoticed in its early stages, in part because symptoms are pretty common and can be attributed to a number of different illnesses. Weight gain, fatigue, and an increased sensitivity to cold are often some of the first effects people notice.
Hyperthyroidism, or “overactive thyroid,” is essentially the opposite; this condition causes an acceleration in metabolism, which can lead to sudden and dramatic weight loss. Irritability and anxiety are also common symptoms. Both overactive and underactive glandular problems can usually be corrected with medication, often in the form of synthetic hormones.
Irregular Growth Issues
Not all thyroid problems center on hormone production. Goiters, for example, are lumps on the throat that happen when the gland becomes inflamed. These are mostly benign, but at times they can compress the trachea or esophagus, which can make it hard to breathe or swallow. Thyroid nodules are similar; these are lumps that grow on the surface of the gland, usually in response to some sort or irritant but sometimes simply as a matter of course. Both can be removed surgically.
Thyroiditis is an inflammatory condition within the gland that often brings about pain and fever and has a wide variety of causes. This condition is easily treatable, and the symptoms usually go away on their own. On the more serious end of the spectrum is thyroid cancer. This particular type of cancer is usually very treatable, but a lot depends on how early the condition is caught and whether or not it has spread.
