Very often in practice to specify, exclude or diagnose gynecological conditions it is necessary to measure the levels of various sex hormones such as gonadotropic hormones, prolactin, estrogens and others. For example, depending on the purpose of the study, the determination of GHT (gonadotropic hormones) is done on different days of the menstrual cycle. Not infrequently, the levels of some steroid, sex hormones are also released. You can learn more about the subtle hormonal regulation of the menstrual cycle here. To determine the basic/basal level, blood is taken only from the 3rd to the 7th day from the start of menstrual bleeding, and the test is done for all three hormones – follicle-stimulating FSH, luteinizing LH and prolactin. FSH and LH values ​​in the early phase of the cycle in healthy women are approximately 5-15 international units per liter (IU/l), with a ratio equal to about 1:1 to 1:1.5. In the same phase of the cycle, prolactin is usually around 320-480 IU/l, but since this hormone is easily variable, values ​​up to 800 are considered physiological in some cases. NEWS_MORE_BOX To determine ovulation, the hormone test is done around the 14th day of the cycle, when it is believed that ovulation should occur. Their levels during ovulation in healthy women are at least 2 times higher for FSH and 3-4 times higher for LH. Changes in hormone levels can direct clinical thought to certain conditions or diseases. For example, high values ​​of LH and FSH in the early phase of the cycle are a sign of menopausal changes occurring in the hormonal gynecological axis. However, the absence of an increase in gonadotropin hormone levels around day 14 indicates a lack of ovulation. On the other hand, the changed ratio between LH and FSH from 1:1 to 2:1 or 3:1 in favor of LH in the first phase of the cycle is a very important sign of the presence of ovarian hyperandrogenemia (in other words – polycystic ovary syndrome. The increase A prolactin level above 800 IU/l can be a sign of an increase in the cells that produce it in a structure in the brain called the pituitary gland the probability of the presence of a growth/tumor of the pituitary gland. In addition to gonadotropic hormones, estrone, estradiol, progesterone, testosterone, free testosterone, sex hormone-binding globulin and others are also examined. All steroid hormones except estradiol and Progesterone is usually determined in the early follicular phase of the menstrual cycle (5th – 7th day). For more information about these hormones and the clinical interpretation of their values, follow the upcoming articles.