This test measures the level of luteinizing hormone (LH) in your blood. LH is made by your pituitary gland, a small gland located underneath the brain. LH plays an important role in sexual development and functioning.
- In women, LH helps control the menstrual cycle . It also triggers the release of an egg from the ovary. This is known as ovulation. LH levels quickly rise just before ovulation.
- In men, LH causes the testicles to make testosterone , which is important for producing sperm. Normally, LH levels in men do not change very much.
- In children, LH levels are usually low in early childhood, and begin to rise a couple of years before the start of puberty . In girls, LH helps signal the ovaries to make estrogen . In boys, it helps signal the testes to make testosterone.
Too much or too little LH can cause a variety of problems, including infertility (the inability to get pregnant), menstrual difficulties in women, low sex drive in men, and early or delayed puberty in children.
Other names: lutropin, interstitial cell stimulating hormone