The LH test measures the level of luteinizing hormone in the blood. LH is a hormone produced by the pituitary gland and plays a key role in regulating the reproductive system in both males and females.

• In females, LH helps control the menstrual cycle and triggers ovulation (the release of an egg from the ovary).
• In males, LH stimulates the production of testosterone by the testes, which is essential for sperm production and male sexual development.