The thyroid gland is found in the front of the neck and produces two main hormones. The hormones are called thuroxine (T4) and Triiodothyronine (T3). Together these hormones regulate the body’s metabolism by increasing energy use in cells, regulate growth and development, help to maintain body temperature and aid in oxygen consumption. These two hormones are regulated by hormones produced by the hypothalamus and pituitary gland. The hypothalamus senses changes in body’s metabolic rate and releases a hormone known as thyropin-releasing hormone (TRH). This hormone then flows through connecting vessels to the pituitary gland which signals it to release another hormone. This hormone is known as thyroid-stimulating hormone (TSH). TSH then makes its way to the bloodstream until it reaches the thyroid where it is then signaled to activate T3 and T4 production . This mechanism is controlled by a negative feedback loop meaning that when there is a sufficient amount of thyroid hormones in the blood stream, this will signal back to stop production of thyroid stimulating hormones. Complications occur when the thyroid hormones keep increasing even though there is already a sufficient amount of T3 and T4 in the blood stream. This process of over expression of thryroid hormones is known as hyperthyroidism. Hyperthyroidism is a general term that includes any disease that has a consequence of an overabundance of thyroid hormones. Hyperthyroidism is a general term but there are many variant diseases that are in the hyperthyroidism category. These diseases include diffuse toxic goiter, Basedow’s disease, thyrotoxicosis, Parry’s and Graves’ disease.
1. Overview of patient phenotype
Hyperthyroidism has a plethora of causes. The major causes of hyperthyroidism are thyroid nodules, over consuming iodine, inflammation of the thyroid and Graves’ disease. The main cause of hyperthyroidism Graves’ disease which affects quite a few people in the general population. This disease is characterized as an autoimmune disorder. This means that the body makes antibodies known as thyroid stimulating immunoglobulin that bind and over activate the production of thyroid hormones . So in essence the antibody mimics the thyroid stimulating hormone and when the negative feedback loop is in affect the antibody still binds to the thyroid and T3 and T4 are over produced .
Thyroid nodules are lumps in the thyroid often called adenomas. These adenomas are quite common affecting around seven percent our countries population. These lumps on the thyroid can become very active and thus produce a large amount of thyroid hormone. In some cases hyperthyroidism is brought on by consuming too much medication that treats an underactive thyroid.
There are many causes of hyperthyroidism, but the symptoms of hyperthyroidism are the same no matter what causes the over expression of thyroid hormones. The main symptoms of hyperthyroidism are fatigue, shortness of breath, weak muscles, anxiety,...