Diseases of the Thyroid Gland

The thyroid is one of the biggest endocrine glands in the body. It is responsible for controlling protein production, the body's rate of energy consumption, and the body's sensitivity to other hormones. The thyroid gland participates in all these processes by producing thyroid hormones like triiodothyronine (T3) and thyroxine (T4). These hormones control the rate of metabolism and affect the growth, as well as the rate of function of some systems in the body. Iodine is present both in T3 and T4. The thyroid gland is controlled by the pituitary and the hypothalamus.

What are the diseases of the thyroid gland and their causes?

HYPOTHYROIDISM

Hypothyroidism is a disease characterized by the insufficiency of thyroid hormone. There are many possible causes of this health problem. They include: iodine deficiency (the most common worldwide), hormone deficiency from either the pituitary or hypothalamus, and a defect in the thyroid gland. Meanwhile, temporary hypothyroidism can be caused by the Wolff-Chaikoff effect. Hypothyroidism can be categorized into three depending on their organ of origin: primary (thyroid gland), secondary (pituitary gland), and tertiary (hypothalamus)

What are its symptoms?
In adults, the symptoms of hypothyroidism may include: slowed speech, a breaking and hoarse voice, deepening of the voice, impaired memory, impaired cognitive function, urticaria (hives), migraine, increased sensitivity to cold and heat, slow heart rate with changes in ECG, decreased cardiac output and contractility, pericardial effusions, sluggish reflexes, dry puffy skin, hair loss, depression, weight gain, anemia, slowed metabolism, constipation, fatigue, anxiety, difficulty in swallowing or choking sensation, shortness of breath, impaired ventilatory responses to hypoxia and hypercapnia, increased need for sleep, joint pain and muscle cramps, brittle fingernails, osteoporosis or osteopenia, paleness, irritability, yellowing of the skin, abnormal menstrual cycle, decreased GFR and impaired renal function, instability of mood, acute psychosis, muscle hypotonia, decreased sexual drive, and inattentiveness. In pediatric patients, the following additional symptoms may be experienced: mental retardation and short stature.

Treatment for Hypothyroidism
A patient suffering from hypothyroidism may take a synthetic thyroid supplement on a daily basis in order to replace the missing hormone. The American Thyroid Association warns against the intake of herbal remedies. It also warns that iodine overdose can worsen both hyperthyroidism and hypothyroidism.

Prevention of Hypothyroidism
Hypothyroidism can be prevented by taking supplemental iodine. It may also help to be aware of the risks factors such as age for early diagnosis and immediate treatment. The TSH testing is encouraged for some high risk groups like women aged 50 years or above.

HYPERTHYROIDISM

Hyperthyroidism is characterized by the excess of circulating free triiodothyronine (T3) or free thyroxine (T4), or both. This condition results from the overproduction of thyroid hormone. In humans, the major causes of hyperthyroidism include: Grave's disease, toxic thyroid adenoma, toxic multinodular goiter, and AIDS. The intake of medicines like Amiodarone (a heart medication) can also cause the development of hyperthyroidism.

What are its symptoms?
The symptoms of hyperthyroidism include: weight loss, intolerance to heat, weakness, fatigue, irritability, hyperactivity, depression, apathy, sweating, and polyuria. But patients may also experience additional symptoms like: arrhythmias (atrial fibrillation), palpitations, dyspnea (shortnes of breath), decrease of sexual drive, vomiting, nausea, and diarrhea. In elderly patients, many of the classical symptoms may not be present. Meanwhile, the neurological manifestations of the disease may include: tremor, myopathy, chorea, and periodic paralysis. One of the most severe compications of hyperthyroidism is stroke of cardioembolic origin as a result of coexisting atrial fibrillation.

Treatment for Hyperthyroidism
Currently, there are four major and generally accepted treatments for hyperthyroidism: surgery, radioiodine, thyrostatics, and beta-blockers.

Surgery. This medical procedure is done in order to remove a part or the whole thyroid gland. This treatment is not used extensively because the most common forms of hyperthyroidism can be treated effectively by radioiodine.

Radioiodine. In this treatment, radioactive iodine is taken orally on a one-time basis in order to destroy the function of a hyperactive gland. It must be noted that the iodine used in a scan is different from the iodine given for treatment. Radioactive iodine is given to a patient after undergoing a routine iodine scan.

Thyrostatics. Thyrostatics are medicines that stop the production of thyroid hormones. These drugs are believed to work by arresting the iodination of thyroglobulin by thyroperoxidase. Two drugs under this category are PTU (propylthiouracil) and methimazole (Tapazole)

Beta-blockers. Rather than treat, beta-blockers conceal common symptoms of hyperthyroidism like trembling, palpitations, and anxiety. Metoprolol is used frequently as a supplementary treatment for patients suffering from hyperthyroidism.

Prevention of Hyperthyroidism
There are no preventative methods for naturally occurring hyperthyroidism because the disease can be inherited or caused by other unknown or unexplained factors. But it does help to have knowledge of one's family history regarding the disease. It is also important to be aware of the early signs and symptoms of hyperthyroidism.