The thyroid is a butterfly-shaped gland located at the back of the neck. It is made of two lobes that are separated by the isthmus. This is the gland responsible for the production of the hormone thyroxine.. This hormone is produced by follicular cells and they are the ones that play a major role in controlling your metabolism, heart rate, energy level, and body temperature.

A healthy thyroid gland functions normally and controls the level of thyroxine in our body. The problem begins when the thyroid begins producing excess thyroxine. This condition is known as hyperthyroidism, or overactive thyroid disease. A person having this kind of condition would experience a sudden increase in their metabolism rate, which results to sudden weight loss. Aside from that, the patient may experience palpitations, an irregular heartbeat, excessive sweating, and nervousness. Usually, patients undergo fatigue but are unable to sleep at night. Severe hyperthyroidism causes shortness of breath, chest pains, and a weakening of the muscles. Other symptoms include lack of tolerance to heat, insomnia, very light or nonexistent monthly periods for women, and hair loss.