Luteinizing Hormone (LH) Test is a laboratory test used to measure the level of luteinizing hormone in the blood, which is produced by the pituitary gland. This hormone plays a key role in regulating the menstrual cycle in women by stimulating ovulation and coordinating the production of sex hormones such as estrogen and progesterone. In men, luteinizing hormone helps stimulate the production of testosterone, which affects fertility and sexual health. This test is used to diagnose various conditions, including menstrual disorders, infertility, polycystic ovary syndrome (PCOS), and to assess the function of the gonads. The test is performed by drawing a blood sample, and women are usually asked to take the test on specific days of their menstrual cycle to obtain accurate results. The LH test is part of a comprehensive evaluation of the reproductive system, and the results should be interpreted by a physician based on medical history and clinical symptoms.