Beckman Coulter 33515 Access hLH Calibrator (S0-S5)

What are luteinizing hormone test levels (LH test levels)

This test measures the level of luteinizing hormone (LH). A hormone is a chemical messenger in your bloodstream that controls the actions of certain cells or organs. LH is usually measured in a sample of your blood. But in certain cases, it may be measured in urine (pee).

LH plays an important role in sexual development in children and fertility in adults:

• In women who menstruate (have periods), LH helps control the menstrual cycle. It also triggers the release of an egg from the ovary. This is called ovulation. LH levels quickly rise just before ovulation. If you’re trying to have a baby, this monthly increase in LH tells you when you’re most likely to become pregnant.
• In men, LH causes the testicles to make the hormone testosterone, which is important for making sperm. Normally, LH levels in men do not change very much.
• In children, LH levels are normally low in early childhood. They begin to rise slowly in the years before puberty, usually between ages six and eight. As puberty begins LH continues to rise along with levels of other hormones. The increase in all of these hormones triggers the physical changes of puberty:
  • In girls, LH helps signal the ovaries to make the hormone estrogen. Estrogen is involved in the growth of breasts, body hair, and the start of menstruation.
  • In boys, LH helps signal the testicles to make testosterone. Testosterone is involved in the growth of facial and body hair, changes in a boy’s voice, and sperm production.

LH levels are controlled by a complex system of hormones made in different parts of your body. Abnormal levels of LH may be a sign of a problem with any of these parts. They include your:

• Pituitary gland, a small gland at the base of your brain. It makes LH.
• Hypothalamus, a part of your brain. It makes hormones that tell your pituitary gland how much LH to make.
• Reproductive glands, your ovaries or testicles. The amount of sex hormones they make let your hypothalamus and pituitary gland know when to start and stop making LH.

Other names: lutropin, interstitial cell stimulating hormone, ICSH

What is it used for?

LH testing is used to help diagnose conditions that cause too much or too little LH. The specific way the test is used depends on your sex, age, and symptoms.

In women, an LH tests may be used to:

• Help find the cause of infertility.
• Find out when ovulation is about to happen if a woman is trying to get pregnant. Usually at-home tests are used to track ovulation. These tests measure LH in urine (pee).
• Check for medical conditions that affect the ovaries.
• Find the reason for irregular or stopped menstrual periods in women of childbearing age.
• Help find out if menopause, or perimenopause may have begun:
  • Menopause happens when the ovaries stop making certain hormones, and menstrual periods have stopped for 12 months in a row. This usually happens around age 50.
  • Perimenopause is the time leading up to menopause when hormones and periods begin to change. It usually starts around age 45.

In men, an LH test may be used to:

• Help find the cause of:
  • Infertility
  • A low sperm count
  • Low testosterone levels
  • A low sex drive
• Check for medical conditions that affect the testicles

In women and men, LH testing may be used to help diagnose disorders of the:

• Pituitary gland
• Hypothalamus

In children and teens, LH testing is most often used to help find out if a medical disorder is causing early or delayed (late) puberty.

An LH test is usually used with a blood test to check the levels of another hormone called follicle-stimulating hormone (FSH). These two hormones work closely together to control sexual development and reproduction. Blood tests to check estrogen, testosterone, and progesterone levels are also commonly used with LH testing.