The thyroid gland, known medically as the glandula thyreoidea, is responsible for many bodily functions: of which metabolism and growth are two of the major ones. When the thyroid gland isn’t functioning well, the entire body is affected.

The thyroid gland produces two main hormones, namely Triiodothyronine, also known as T3, Tetraiodothyronine, also called thyroxine or T4 Calcitonin, into the blood stream to facilitate these bodily functions, and a healthy thyroid can adapt the amount of hormones released to tailor the amount of hormones that are needed.

What is it and where is it located in the body?

The thyroid is surrounded by two fibrous capsules and is located in the lower half of the throat. It weighs approximately 40 to 60 grams at full growth, but this varies from person to person.

The outer capsule is connected to the voice box muscles and many important vessels and nerves, explains the NCBI. There is loose connective tissue between the inner and the outer capsule, so the thyroid can move and change its position when we swallow.

The thyroid gland works in conjunction with the pituitary gland to ensure that the proper amount of hormones is released. When the thyroid releases too few hormones, it is known as hypothyroidism. When it releases too much of the hormones, it is known as an over active thyroid, or hyperthyroidism.

Only T3 and T4 are proper thyroid hormones, which consist mostly of iodine.
T3 and T4 hormones increase the basal metabolic rate, raising body temperature and pulse rate and they allow for brain and body growth and activate the nervous system.

Symptoms of overactive thyroid

People who suffer from hyperthyroidism experience rapid weight loss, anxiety and restlessness. Many complain of difficulty sleeping, an excess of energy and a protruding thyroid gland. Some people experience the opposite and feel tired and fatigued all day, no matter how many hours of sleep they get.

Heart palpitations are also a common symptom.

Symptoms of an underactive thyroid

Rapid weight gain is the one symptom that separates hyperthyroidism from hypothyroidism.

Slow movements and painful muscles and joints, depression and constipation, as well as sensitivity to cold are also all symptoms of an underactive thyroid.