This butterfly-shaped gland can be found in the lower part of your neck. The two “wings” fold around your windpipe. The thyroid is responsible for secreting hormones: T3 (trio-iodothyronine) and T4 (thyroxine) into the bloodstream. These substances deliver energy to the cells of the body.
Here is how the system works. The thyroid helps regulate your metabolism along with the pituitary gland and the hypothalamus. When the body needs more energy, a chain reaction is touched off.
The hypothalamus is first to respond. It releases TRH (thyrotrophin releasing hormone). This then signals the pituitary to produce TSH (thyroid stimulating hormone). The message it sends to the thyroid is to produce T4. This hormone hangs around in the bloodstream until it is needed. T4 doesn’t have a direct job in the cycle except to be converted to T3 which produces the energy the body needs.
When T3 is needed, the T4 is converted. It then increases the metabolic rate throughout the body cells. It initiates the fight-or-flight response in the body (heart rate increases; fats are broken down for energy consumption). The entire body starts producing energy.
The thyroid has two jobs normally. It helps enzymes needed by the cells to pass through the cell membranes. Inside the cell, it helps the mitochondria (the powerhouse of the cell) to produce energy.
The thyroid, like other glands and organs, can have problems. The two that most people are familiar with are hypothyroidism and hyperthyroidism. The latter is often blamed for weight gain or the inability to lose weight. Actually not as many people as claim to have a thyroid condition at the heart of that problem, but some do.
During hypothyroidism, the thyroid is not producing enough energy for the body. This can lead to weight gain, tiredness, depression, dry skin and dry nails. It can be due to a lack of sufficient iodine in the system. Another reason could be Hashimoto’s disease, an autoimmune disease where the body begins producing antibodies against the thyroid causing it to slow down hormone production.
Hyperthyroidism can have the opposite effect. It can be linked to overactive nodules within the thyroid, inflammation of the thyroid or an autoimmune disease called Graves’ disease. In any case, the thyroid shoots into overdrive and produces more hormone than the body needs. That can lead to weight loss, muscle weakness, sleeplessness and other symptoms.
Thyroid diseases like these two affect men and women, but mostly women. If you suspect that you may have a problem with your thyroid based on the symptoms listed above, see a doctor for further testing.