A gland called the hypothalamus is at the base of the brain, it works as a control center for hormones. The hormones of the hypothalamus regulate the secretion of pituitary hormones which controls the ovary and ultimately the health of the uterine lining as well.
The hypothalamus is connected directly to multiple brain structures, including the pituitary gland; and thus controls secretion through special blood channels that do not really reach the general circulation.
The control hormones of the hypothalamus that in tern regulate the pituitary gland include Gonadotropin-releasing hormone (GnRH), Cortiocotropin-releasing factor (CRH), Growth hormone-releasing factor (GHRH), and thyrotropin -releasing hormone (TRH). These hormones control pituitary hormones of the cycle like FSH, the adrenal gland hormones that controls cortisol, the regulation of growth hormone and ultimately the regulation of the thyroid.
Often patients are told we are ‘checking on your hormone level” but it’s important to remember that all hormones are controlled by a delicate feedback between the hormones and the control hormones and you are almost never going to get all pieces of the puzzle from one blood level.
Because these hormones are released in bursts a single blood test can be confusing.
None the less, there are scientific studies that will give us clues as to how to manage testing and treatment. Its complex, but can help your gyno get a window into your hormonal world to have testing then get recommendations.