The test measures the amount of FSH in the blood. FSH (follicle stimulating hormone) is made in the pituitary gland, an important organ in the brain for making hormones. Production and function of FSH and LH (luteinizing hormone) are closely related.
In women, both hormones play an important role in the growth and maturation of follicles, containing eggs, during the first two weeks of the menstrual cycle. In this phase, they stimulate FSH together with LH the production of the female sex hormone, estradiol. After ovulation, the LH together with FSH for the production of progesterone. This, in turn, ultimately inhibits the production of LH and FSH, so that at the beginning of menstruation all hormones are again present in a low concentration. In pregnancy, the pregnancy hormone hCG the stimulation of progesterone production over. Progesterone is necessary for the implantation of the fertilized egg. During the menopause, the function of the ovaries decreases and the amount of FSH in the blood.
In men, stimulates FSH The production and maturation of sperm cells. Together with LH it also stimulates the production of the male sex hormone testosterone. FSH is relatively constant in men from puberty onward.