Hyperthyroidism

The thyroid is a large endocrine gland located in the neck, below what is known as the Adam's apple in men. A butterfly shaped organ, it receives its blood supply from the superior thyroid artery and affects many vital functions in the body, such as sensitivity to hormones, protein creation and how energy is burned.

Hyperthyroidism occurs when there is overactive tissue within the thyroid gland, causing it to overproduce and release an excess of the circulating free thyroid hormones thyroxine (T4) and triiodothyronine (T3). Other hormones produced in the thyroid assist in regulating calcium levels.

Graves' Disease

The most common cause of hyperthyroidism is Graves' disease, an auto immune disorder that attacks the thyroid, causing it to produce more hormones than necessary, which in turn causes neurological and arterial complications such as nervousness and an heartbeat irregularities. Graves' disease also causes extreme fatigue.

Endocrineweb states that Graves' disease affects women much more often than men, at a about an 8:1 ratio. It is often called "diffuse toxic goiter" because the entire thyroid gland is enlarged, usually moderately enlarged, and sometimes quite big. Graves' disease is uncommon in those over 50, more commonly seen in people in their 30s and 40s, and tends to run in families, though it is not known why.

Other Causes of Hyperthyroidism

A "hot" nodule is a single nodule located within one part of the thyroid. Usually non-cancerous, the nodule produces extreme amounts of thyroid hormone.

Thyroiditis, an inflammation of the thyroid gland, can also cause hyperthyroidism. There are various types of thyroiditis, each one with their own causes and symptoms:

Hashimotos Thyroiditis, also known as chronic lymphocytic thyroiditis, is a disease where the thyroid does not convert iodine into the thyroid hormone, rendering it ineffective. As a result, the thyroid attempts to balance by enlarging itself. Over time, the pituitary gland attempts to stimulate the thyroid into making more of its hormone, causing TSH levels to increase. Eventually T4 decreases, causing the person to develop hypothyroidism. The time span for this occurrence is unknown. In some cases, it can take as short as several weeks or as long as several years.

De Quervain's Thyroiditis, is much less common. This disease causes pain and tenderness as the thyroid englarges. Generally patients with this form of hyperthyroidism will become sick and develop a high fever. Antibiotics are of no use as this type will mimic a virus, though no virus will be detected. Many patients will recover, though some will develop hypothyroidism and require medication.

Silent Thyroiditis develops more commonly in women who were recently pregnant. Though the exact cause is unknown, with this form of thyroiditis symptoms will generally go away on it's own within a year. Over time patients may develop hypothyroidism. It is recommended that those who suffer from silent thyroiditis follow up with their doctor regularly.

Symptoms of Hyperthyroidism

Some symptoms of hyperthyroidism are:

• rapid weight loss, even with an increased appetite
• fast paced heartbeat
• trembling of the hands
• anxiety
• sensitivity to heat, increase sweating
• insomnia
• frequent bowel movements

Blood tests can be administered to determine whether a person experiencing these symptoms has hyperthyroidism. Seek medical attention if the disease is suspected to avoid complications from a thyroid storm.

References
Endocrineweb: Hyperthyroidism
Google Health: Silent Thyroiditis