Luteinising Hormone
Understanding Luteinising Hormone
What is Luteinising Hormone?
The Luteinising Hormone test measures the amount of luteinizing hormone (LH) in your blood. LH is vital in maintaining a healthy reproductive system in both men and women. This test is performed to evaluate the health of the reproductive organs, irregularities in menstrual cycles, fertility issues, and early or late puberty.
Luteinizing hormone (LH) is produced by the pituitary gland, a pea-sized gland situated at the base of the brain. LH is essential for the sound reproductive health of both men and women. In women, LH helps regulate the menstrual cycle by triggering the release of an egg from the ovary (ovulation). It also stimulates the production of progesterone, a hormone necessary to maintain pregnancy. In men, LH stimulates the production of testosterone, which is required for the production of sperm. Thus, LH also plays a significant role in puberty and fertility in men. Fluctuations in the level of this hormone can lead to various health-related problems that may need medical interventions.
The Luteinising Hormone test may be recommended for women with symptoms such as irregular or heavy periods, polycystic ovarian syndrome (PCOS), and difficulty getting pregnant. It also helps to determine ovulation time in females, evaluate those suspected of hypogonadism (a condition where little or no sex hormones are produced in both males and females), and evaluate the function of the pituitary gland. In men, a Luteinising Hormone test may be performed in suspected cases of low sperm count, fertility issues, or signs of low testosterone levels such as a decreased sex drive, low muscle mass, etc. It is often performed in conjunction with other hormonal tests such as follicle-stimulating hormone (FSH) test or prolactin test for a detailed reproductive health evaluation.
In women, the preferred time to collect the sample is the second or third day of the menstrual cycle. For men, the test can be done at any time. Your doctor may ask you to temporarily stop taking certain medications, such as birth control pills, so it is best to let your doctor know about all the medicines you might be taking to get accurate test results.
Lab test results may vary across different laboratories. Abnormal test results require an expert interpretation; therefore, never try to self-medicate at home based solely on these results, and always consult a doctor for a proper understanding of the test results. Discuss your symptoms and medical history to help the doctor correlate your clinical and laboratory findings. These details and test results guide doctors in suggesting lifestyle modifications such as diet and exercise.
What is Luteinising Hormone used for?
The Luteinising Hormone test is done to:
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Evaluate the function of reproductive organs (ovaries or testicles).
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Assess menstrual irregularities and conditions such as amenorrhea or oligomenorrhea.
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Detects disorders of the pituitary gland or diseases involving the ovaries.
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Evaluate infertility issues in men and women.
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Evaluate low sperm count in men.
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Assess hypogonadism or gonadal failure in men.
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Assess testicular dysfunction in men.
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Evaluate early or delayed sexual maturation (puberty) in children.
What does Luteinising Hormone measure?
The Luteinising Hormone test determines the level of luteinizing hormone that promotes the functioning of the gonads, i.e., testes in men and ovaries in women. LH is produced by the pituitary gland, a pea-sized gland situated at the base of the brain. The production and release of LH are controlled by a system known as the hypothalamic-pituitary-gonadal axis. A hormone called GnRH is released from the hypothalamus of the brain and binds to the cell receptors in the anterior pituitary gland, which in turn prompts the synthesis and release of luteinizing hormone. LH then travels across the blood and attaches to its target cells in the testes in men and ovaries in women to facilitate optimal sexual and reproductive activities.
Interpreting Luteinising Hormone results
Interpretations
The following values are considered to be normal, LH blood levels measured in international units per liter (IU/L):
Women:
· Follicular phase of the menstrual cycle: 1.9 to 12.5 IU/L
· LH surge: 8.7 to 76.3 IU/L
· Luteal phase of the menstrual cycle: 0.5 to 16.9 IU/L
· Pregnancy: less than 1.5 IU/L
· Post-menopause: 15.9 to 54.0 IU/L
· Women using contraceptives: 0.7 to 5.6 IU/L
Men:
· Age group of 20 and 70 years: 0.7 to 7.9 IU/L
· >70 years of age: 3.1 to 34.0 IU/L
Reference values may vary from lab to lab*