Why would an imbalance in thyroid hormones have such widespread effects on the body?

The thyroid gland is a butterfly-shaped organ located at the base of the neck. It releases hormone which regulates metabolism and important bodily functions such as breathing, heart rate, body weight, muscle strength, menstrual cycles, body temperatures, cholesterol levels and many others. The thyroid is a part of the endocrine system, which is made up of glands that produce, store and release hormones into the bloodstream so the hormones can reach every cell in the body. It uses iodine to produce it two main hormones: triiodothyronine (T3) and thyroxine (T4) which needs to be in balance all of the time. Any imbalance of these hormones would mean irregular body functions. Thyroid disease is a common problem that can cause symptoms because of over- or under- function of the thyroid gland. Thyroid disorders are as follows: hypothyroidism, hyperthyroidism, goiter, thyroid nodules and thyroid cancer. When there is too much T3 or T4 in the body, hyperthyroidism occurs. A person with hyperthyroidism will experience anxiety, irritability or moodiness, nervousness or hyperactivity, sweating or sensitivity to high temperature, hand trembling, hair loss, missed or light menstrual periods. Hypothyroidism, on the other hand, occurs when there is low T3 and T4 in the body and would show as trouble in sleeping, tiredness and fatigue, difficulty concentrating, dry skin and hair, depression, sensitivity to low temperature, frequent and heavy periods, joint and muscle pain. Since most of the major bodily functions are regulated by the hormones produced by the thyroid gland, any overproduction or under production of these hormones would mean malfunction of the body. Any body malfunction which may arise from these irregular hormone production of thyroid gland may be a cause of a more serious illness. 

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