Luteinizing Hormone (LH) Levels Test Test
This test measures the level of luteinizing hormone (LH) in your blood or urine. LH helps control the menstrual cycle and ovulation in women, and testosterone production and sperm development in men. In children, LH levels rise during puberty. The test helps diagnose fertility issues, menstrual problems, early or delayed puberty, and pituitary or hypothalamus disorders.
What this test measures
This test measures the level of luteinizing hormone (LH), a chemical messenger that controls sexual development and fertility. In women, LH triggers ovulation and helps regulate the menstrual cycle. In men, LH stimulates testosterone production and sperm development. In children, LH levels rise during puberty.
What your results mean
Reference ranges vary by laboratory and by your age and sex. MedlinePlus does not publish a single normal range for this test — always read your result against the range printed on your own lab report and discuss it with your provider.
Higher-than-normal results
In women of childbearing age, high LH levels throughout the month may mean the ovaries aren't working properly, possibly due to conditions like PCOS, primary ovarian insufficiency, or Turner syndrome. In women 45 or older, high LH may indicate approaching menopause. In men, high LH can be caused by testicular damage, mumps, injury, or genetic disorders like Klinefelter syndrome. In children, high LH and FSH with early sexual development suggest early puberty.
Lower-than-normal results
Lower-than-normal LH levels in adults often indicate a problem with the pituitary gland or hypothalamus. In women, low LH and FSH with missed periods may be linked to extreme exercise, malnutrition, stress, or being very underweight. In teens with delayed puberty, LH levels may be low, normal, or high depending on the cause.
Frequently asked questions
What is LH and why is it important?
LH (luteinizing hormone) is a chemical messenger that controls sexual development and fertility. In women, it triggers ovulation and helps regulate the menstrual cycle. In men, it stimulates testosterone production and sperm development.
How is the LH test done?
LH is usually measured in a blood sample, but in certain cases it may be measured in urine (pee).
What does a high LH level mean in women?
In women of childbearing age, high LH levels throughout the month may mean the ovaries aren't working properly, possibly due to PCOS, primary ovarian insufficiency, or Turner syndrome. In women 45 or older, high LH may mean approaching menopause.
What does a low LH level mean?
Lower-than-normal LH levels in adults often indicate a problem with the pituitary gland or hypothalamus. In women, low LH and FSH with missed periods may be linked to extreme exercise, malnutrition, stress, or being very underweight.
Can LH testing be used for children?
Yes, in children LH testing helps find out if a medical disorder is causing early or delayed puberty. High LH and FSH with early sexual development suggest early puberty. In teens with delayed puberty, LH levels may be low, normal, or high depending on the cause.
Related lab tests
Sources
- MedlinePlus: Luteinizing Hormone (LH) Levels Test — NIH MedlinePlus
Last updated . Information is aggregated from official public sources and is not a substitute for professional medical care.