FSH LH Test

FSH/LH ratio is used for diagnosing polycystic ovarian syndrome (PCOS), menstrual irregularities, fertility problems, delayed or precocious puberty. This test is also used to assess the hypothalamic-pituitary-gonadal axis.

What is FSH?

In women, follicle stimulating hormone (FSH) helps in the growth of ovarian follicle and also stimulate the ovarian follicle to produce the female sex hormone, estrogen. Thus, this hormone plays an important role in menstruation, ovulation, and puberty.

In men, FSH stimulates the production of testosterone that is necessary for the production of sperms. Thus, FSH plays a major role in regulating the function of testes in men. This hormone plays an important role in puberty and fertility.

What is LH?

Luteinizing hormone is produced by the pituitary gland. It affects the sex organs in both men and women during sexual development. In women, LH works with follicle stimulating hormone (FSH) to stimulate the ovarian follicle to produce the female sex hormone, estrogen. The rise in estrogen stimulates the release of more LH. This cause the ovarian follicle to release the mature egg from the ovary, a process called ovulation and turns the remnants of the follicle into a corpus luteum. If fertilization occurs, the LH stimulates the corpus luteum to produce progesterone. Progesterone is an essential hormone needed to maintain pregnancy. If fertilization does not occur the levels of progesterone drop off leading to the beginning of next cycle. Thus this hormone plays an important role in menstruation, ovulation, and puberty.

In men, LH hormone binds to receptors in Leydig cells present in the testes. This hormone stimulates the production of testosterone from these cells that are necessary for the production of sperms. Therefore, LH plays a major role in regulating the function of testes in men. This hormone plays an important role in puberty and fertility.

Why this test is performed?

This test is performed mainly to asses the functions of reproductive organs, fertility issues, ovulation process and function of the pituitary gland or hypothalamus. In women, your doctor may ask to perform this test if you have irregular or heavy menstrual periods, difficulty in getting pregnant or fertility issues or if you suspect menopause, and to detect any pituitary or hypothalamus problems. In men, your doctor may ask to perform this test if you have a low sperm count, fertility issues, or signs of low testosterone levels such as decreased sex drive, low muscle mass, and to detect any pituitary or hypothalamus problems.

This test result gives a clear diagnosis regarding infertility. The levels of each hormone help to assess the fertility issues, functions of reproductive organs, pituitary gland or hypothalamus.

If the test result falls in the normal reference range generally no medical intervention is necessary.

In women, the increased levels of FSH and luteinizing hormone (LH) may indicate a condition called primary ovarian failure, where the ovaries fail to work properly themselves. There are many causes for this condition such as autoimmune disorders, ovarian tumors, Turner syndrome (a genetic abnormality), polycystic ovary syndrome, menopause, adrenal or thyroid disease etc. In women whose ovaries are not properly developed, who use chemotherapy medicines, or have exposure to radiation therapy also shows increased levels of FSH and LH. Decreased levels of FSH and LH may indicate a condition called secondary ovarian failure. This condition is due to the problem with pituitary or hypothalamus glands. This fails to stimulate the ovaries and ovarian function leading to ovulatory problems.

In men, the increased levels of FSH and LH may indicate a condition called primary testicular failure, where the gonads fail to work properly themselves. There are many causes for this condition such as autoimmune disorders, germ cell tumors, Klinefelter syndrome (a genetic abnormality), viral infection such as mumps, trauma etc. In men whose gonads are not properly developed, who use chemotherapy medicines, or have exposure to radiation therapy also shows increased levels of FSH and LH. Decreased levels of FSH and LH may indicate a condition called secondary testicular failure. This condition is due to the problem with pituitary or hypothalamus glands. This fails to produce sufficient male sex hormone testosterone affecting the development of male characteristics and fertility. Lack of sexual drive, fatigue, low muscle mass, sexual dysfunction is common in men with low testosterone levels.