The thyroid is a gland that is located in the throat, positioned just below the larynx, or voice box. It is shaped like a butterfly with one wing fitting on each side of the windpipe. The thyroid produces a hormone called thyroid hormone, referred to as TH. Thyroid hormone is needed by the body for a number of functions to work normally. TH is used, for example, by the body to produce enzymes that combine glucose and oxygen, a process that increases body heat and increases the basic metabolic rate. TH is also used by the body to regulate the growth of tissue, to maintain blood pressure, and plays a critical role in the development of the central nervous system and the skeletal system. TH also plays a role in the development of the body's reproductive system. According to the National Women's Health Resource Center, the thyroid gland can malfunction in three different ways. These disorders are called hypothyroidism, hyperthyroidism and thyroid nodules.
Hypothyroidism
In hypothyroidism, the thyroid does not produce enough TH, which slows the body's metabolism. Symptoms of hypothyroidism include weight gain, depression, low body temperature, constipation, infertility, high cholesterol, fatigue and dry or itchy skin. Hair can become thin or dry, or it can fall out. The hands, feet and face can become puffy. There can be a husky or hoarse quality to the voice. Other signs include heavy or irregular menstruation, poor memory, muscle aches and the appearance of a goiter, which is an enlarged thyroid.
Hyperthyroidism
This is a condition in which the thyroid produces too much TH, which speeds up the body's metabolism. Symptoms of hyperthyroidism include weight loss, irritability or nervousness, changes in appetite, muscle weakness, trembling in the hands and a heart rate that is irregular or fast. There can be disturbances such as insomnia to sleeping patterns. Menstrual flow can have less than normal volume and be shorter. An intolerance to heat can develop as well as increased perspiration. Bowel movements can become more frequent. Pressure behind the eyes can increase, causing them to bulge. There can also be the appearance of a goiter.
Thyroid Nodules
Thyroid nodules are small lumps that are usually benign groups of thyroid cells that are not functioning properly. Sometimes these nodules can be cysts. A small percentage, about 10 percent, of thyroid nodules turn out to be cancerous. Most thyroid nodules are too small to be detected and do not produce any symptoms. Some can grow large enough to press against the windpipe and make swallowing difficult.
Children
According to the American Association of Clinical Endocrinologists, one out of every 5,000 newborns has the condition of hypothyroidism. Additional symptoms for infants that have hypothyroidism include pallor, sluggishness, constipation, a scalp that is dry and itchy and an increased sensitivity to cold temperatures.
