What is FSH?
Follicle Stimulating Hormone (FSH) is a hormone secreted by Gonadotropic cells of the Anterior Pituitary gland located in the brain. It regulates the development, maturation, and reproductive processes of the gonads in the body. It plays a major role, along with Luteinizing Hormone (LH), also secreted by anterior pituitary gland, in regulation of the sexual development and functioning. Hence both these are measured together most of the time.
Role of FSH
FSH stimulates the maturation of primordial germ cells in both men and women. In women, FSH stimulates follicular growth in ovaries, whereas it sustains spermatogenesis in males by affecting Sertoli cells in the testes. Its effect is in coordination with other hormones like LH, Inhibin etc. Secretion of FSH is regulated by release of Gonadotropin Releasing Hormone (GnRH, from Hypothalamus) and negative feedback effect of Inhibin.
What do the FSH Test results mean?
The meaning of your reported result of FSH test will depend on whether you are a woman, man, or a child. Some of the more common conditions are given below.
Woman, causes for a high FSH test result:
- Primary ovarian insufficiency (POI) or failure which is the loss of ovarian function before the age of 40.
- Polycystic ovary syndrome (PCOS), a common hormonal disorder and one of the leading causes of female infertility as it affects childbearing women.
- Perimenopausal or early menopause
- Ovarian tumour
- Turner syndrome
Woman, causes for a low FSH test result:
- Your ovaries are not producing adequate eggs.
- Your pituitary gland is not functioning correctly.
- There may be a hypothalamic problem, a part of the brain that controls the pituitary gland.
- You are very underweight.
Man, causes for a high FSH test result:
- Damaged testicles - due to radiation, infection, chemotherapy or alcohol abuse.
- Klinefelter syndrome
Man, causes for a low FSH test result:
- Any disease affecting the hypothalamus or pituitary
In children, high FSH with high luteinizing hormone, means puberty is about to start or has already started. If it occurs before the age of 9 years in a girl or 10 years in a boy (precocious puberty), it may indicate an injury to or disorder of the brain. Low FSH and LH levels in children may be a sign of delayed puberty which can be due to disorders of the ovaries or testicles, Turner syndrome in girls, Klinefelter syndrome in boys, any infection, hormone deficiencies, eating disorder etc.