Hypothyroidism or underactive thyroid, which is not producing enough thyroid hormone (T3 and T4). It is one the most undiagnosed and undertreated disease. Let us first understand the physiology of hypothyroidism. The thyroid system starts from the hypothalamus, it releases a hormone called TRH (Thyrotropin-releasing hormone). TRH stimulates the anterior pituitary gland to produce TSH (thyroid-stimulating hormone) which further stimulates the thyroid gland to produce T4(thyroxine) and T3(triiodothyronine). This is like a feedback loop that monitors the levels of T3 and T4. If levels of T3 and T4 are high, signal is sent to the pituitary gland and hypothalamus causing TSH levels to be reduced.
It is important to understand that this feedback loop plays a very important role in the proper functioning of the body and the failure in any of the feedback loop components can lead to disorders. Sometimes taking thyroid medication won’t help as the problem can be related to a different system that is involved including the brain, pituitary gland, and even liver. T4 is not the active thyroid hormone hence it is converted into T3 and the majority of the conversion does not occur in the thyroid gland. The conversion takes place mostly in the liver. So, thyroid disease can also result from poor liver function.
There are various causes of hypothyroidism and one of the most common causes of hypothyroidism is Hashimoto’s disease. In Hashimoto’s disease, there is an immune response of the body against the thyroid gland which causes the decreased function of the thyroid gland. Hypothyroidism is also associated with high blood pressure, cholesterol which can lead to cardiovascular disease. Stress can also be related to thyroid function, the more stressed you are poor will be your thyroid function. Nutrition plays a very vital role in the proper functioning of the thyroid. Low thyroid function is associated with nutritional deficiencies of iodine, selenium, zinc, omega 3, vitamin b complex, vitamin D, vitamin A.
There are various symptoms of hypothyroidism including slow heart rate, depression, dry skin, thinning of hair, feeling tired, fatigue, memory loss, constipation. In women, heavy periods or irregular menstrual periods can be a sign of hypothyroidism.
With the proper diagnosis and right medication, you can consult your doctor to start the exercise regime. Regular exercise will help to prevent weight gain and can counter the effects of your depressed metabolism.