This show we discussed thyroid disease.
The thyroid is a gland that is located in the front of the neck that produces thyroid hormone. Thyroid hormone is important for metabolism in all of our cells.
There are 2 main classes of thyroid disease other than thyroid cancer (we did not talk about thyroid cancer).
Hyperthyroid means that the thyroid gland is overproducing thyroid hormone.
Hypothyroid means that the thyroid gland is underproducing thyroid hormone.
Most common cause of hyperthyroid is Graves disease. This is caused when the body makes antibodies that falsely stimulate the thyroid to produce hormone. Symptoms include weight loss, palpitations, fast heart rate, heat intolerance, fatigue, protruding of the eyes.
Hypothyroid has a few causes but the most common is Hashimotos thyroiditis. This is occurs when the body makes antibodies that destroy the cells that make thyroid hormone. Symptoms of hypothyroid include fatigue, weight gain or difficulty losing weight, dry skin or hair, hair loss, depression, memory and cognition decline, among others.
Thyroid hormone is produced in two forms, T3 and T4. The thyroid gland produces mostly T3 and less T4. The hormones are released into the circulation and go to all the cells of the body. Inside the cells, T3 is converted to T4, which is the active form.
Thyroid hormone production is regulated by other hormones. TSH (thyroid stimulating hormone) is produced in the pituitary gland and stimulates the thyroid to make thyroid hormone. This process is regulated by a negative feedback loop which means when thyroid hormone is low, TSH production is increased which stimulates the thyroid gland to produce more thyroid hormone, as the levels normalize, TSH levels go back down. Because of this feedback loop, we monitor TSH levels for adequate thyroid hormone production or when people are treated with thyroid hormone replacement.
Hypothyroidism is treated with thyroid hormone replacement. It is usually treated with levothyroxine (T4) which is a synthetic bioequivalent form. It is converted to T3 in the cells where it is needed.
