Luteinizing hormone is a hormone that helps regulate reproductive processes in males and females. It is produced by the pituitary gland. In women, luteinizing hormone helps regulate the menstrual cycle and ovulation. In men, this hormone stimulates the production of testosterone, which plays an important role in producing sperm. Determining the amount of luteinizing hormone present is a common step in investigating infertility in women and men.
In women, the amount of luteinizing hormone present in the body varies throughout the menstrual cycle. The hormone increases rapidly just before ovulation occurs. A hormone analysis can be used for evaluating irregularities in women’s menstrual cycles, determining menopause, and determining early and late puberty in children.
A test for luteinizing hormone can determine whether a woman is ovulating. This can be done as a urine test. These tests can help women determine when the most fertile days of their menstrual cycle are. Home tests are available in the drugstore. Women can also use fertility awareness methods, such as taking their basal body temperature and noting their vaginal secretions to monitor the surge of hormone that indicates their most fertile days.
Other analyses of luteinizing hormone require a blood test. Because the amount of this hormone changes for women during a menstrual cycle, tests may need to be performed over several days. Many conditions can change hormone levels, including some medications. Normal hormone levels vary not only during a woman’s menstrual cycle, but also according to age and sex.
Abnormally high levels of this hormone may indicate that women’s ovaries are not functioning, have been removed, or early puberty in girls. High levels of the hormone in men may indicate that the testicles are not functioning or have been removed, or Klinefelter syndrome. Low levels in women and men may indicate an eating disorder, stress, failure of the pituitary gland, damage to part of the brain, or low body weight.