What is luteinizing hormone (LH)?

Luteinizing hormone (LH) is a hormone produced in both men and women produced by the pituitary gland that is essential for reproduction. It plays a role in many events including puberty, menstruation, and fertility. LH testing is done for the following conditions:

• inability to become pregnant
• irregular or missed periods
• early signs of puberty
• delayed puberty

LH rises just before ovulation and using the ovulation predictor kit (OPK) you can detect the LH surge and subsequent ovulation.

Normal values of luteinizing hormones (LH)

Normal result for an adult women are:

Before menopause: 5 to 25 IU/L
Level peaks even higher around the middle of the menstrual cycle
Level then becomes higher in women after menopause: 14.2- to 52.3 IU/L
LH levels are normally low during childhood.

Normal result for men over 18 years of age is around 1.8 to 8.6 IU/L.

Higher than normal levels of LH in women are seen:

• When women of childbearing age are not ovulating
• When there is an imbalance of female sex hormones (such as with polycystic ovary syndrome)
• During or after menopause
• Turner syndrome
• When the ovaries produce little or no hormones (ovarian hypofunction)

Higher than normal levels of LH in men may be due to:

• Absence of testes or testes that do not function (anorchia)
• Problem with genes such as Klinefelter syndrome
• Endocrine glands that are overactive or form a tumor (multiple endocrine neoplasia)