When the body uses these hormones, the thyroid creates more to replace them. The pituitary gland monitors the amount of the thyroid hormones in the bloodstream and adjusts the production of its own hormone accordingly. The pituitary gland also sends this information to the thyroid gland so the latter knows how much hormone it needs to produce (Endocrine Web, 2006a)
Thyroid diseases occur when the thyroid gland produces more hormones, which prompts the body to consume more energy. This disorder is called hyperthyroidism. When the thyroid gland produces fewer hormones, the body is prompted to lessen its energy consumption. This condition is called hypothyroidism (American Academy of Otolaryngology, 2006)
Thyroiditis, a disease which can either be painless or painful, can trigger the thyroid gland to produce more hormones, thus, causing hyperthyroidism to occur in short periods of time. The painless type usually happens to women who have just given birth.
The symptoms of hyperthyroidism include severe irritability and nervousness, muscle tremors, unpredictable and infrequent menstrual periods in women, sudden weight loss, inability to sleep, enlarged thyroid, eye irritation, and sensitivity to heat. The symptoms of hypothyroidism are fatigue, heavy and frequent menstrual periods in women, severe forgetfulness, sudden weight gain, dry hair and skin, raspy voice, and sensitivity to cold (The Cleveland Clinic, 2006)
Doctors perform various thyroid diagnostic tests to determine if the thyroid gland is functioning well. These tests include the T3 and T4 tests, the TSH (thyroid stimulating hormone) test, and ultrasound of the thyroid gland. The TSH test is usually done first, as it is the best measure of how well the thyroid gland functions. When the blood levels of TSH is high, the thyroid glad is under active; and when it is low, the thyroid gland