Your thyroid gland is a small, butterfly shaped gland that lies directly under the muscles in the front of your neck. The thyroid gland produces different hormones that directly control your metabolism, which includes breathing, blood circulation, food digestion, body temperature control and proper functioning of your brain and nerves. If you have a thyroid disease, all of these body processes may be affected.
Physiology
The thyroid gland produces two main hormones: triiodothyronine and thyroxine. When necessary, your thyroid gland releases these hormones and they travel through your bloodstream until they reach your cells. Once in your cells, the thyroid hormones perform their specific functions. The production and release of the thyroid hormones is controlled by another hormone produced by the pituitary gland, called thyroid-stimulating hormone, or TSH.
Hyperthyroidism
Hyperthyroidism is a condition that occurs when your thyroid gland is overactive, which means it produces too much of the thyroid hormone, thyroxine. Excess amounts of thyroxine in your body lead to an increase in metabolism, which can result in a variety of symptoms including excessive weight loss, rapid heartbeat, increased appetite, nervousness, anxiety, tremor, fatigue, muscle weakness and difficulty sleeping. Your thyroid gland may also become physically enlarged and visible in the front of the neck. This condition is referred to as goiter.
A number of conditions, including Graves' disease and tumors on the thyroid can cause hyperthyroidism. Hyperthyroidism may also be caused by chronic inflammation of the thyroid gland, a condition called thyroiditis. There are several different treatments for hyperthyroidism and specific treatment depends on individual factors, according to MayoClinic.com.
Hypothyroidism
Hypothyroidism is characterized by an underactive thyroid gland. If you have hypothyroidism, your thyroid gland does not produce adequate amounts of the thyroid hormones. As a result, all of the processes that make up your metabolism slow down. Hypothyroidism is characterized by excessive weight gain, fatigue, puffiness of the face, constipation, thinning hair, intolerance to cold, joint and muscle pain and a decrease in heart rate.
Hypothyroidism may be caused by thyroiditis, radiation treatment, certain medications or congenital disorders. Treatment for hypothyroidism usually involves regular supplementation of synthetic thyroid hormones.
Considerations
If you believe you have a thyroid disease, it is important to seek treatment as soon as possible. Abnormal amounts of thyroid hormones in the body can cause significant increases or decreases in heart rate that can lead to serious heart conditions.
