Luteinizing Hormone (LH) Levels Test
Reviewed
Also called: LH test, lutropin test, interstitial cell stimulating hormone test
This test measures the level of luteinizing hormone (LH). LH is usually measured in a sample of your blood.
Specimen: blood
Why this test may be ordered
- To help find the cause of infertility in women and men.
- To find out when ovulation is about to occur (often done with at-home urine tests).
- To check for medical conditions that affect the ovaries or testicles.
- To help diagnose disorders of the pituitary gland or hypothalamus.
- To help evaluate early or delayed puberty in children and teens.
Preparation and collection
You may need to stop taking certain medicines or supplements before your test. Tell your provider everything you take. But don't stop taking any prescription medicines unless your provider tells you to. If you have menstrual periods, you may need to have your test at a specific time during your menstrual cycle.
A health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes. If you're using at-home urine testing to track ovulation, follow the instructions that come with your LH testing kit.
There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly. There is no risk to a urine test.
Understanding results
To understand the results of your LH test, your provider will consider your sex, age, symptoms, medical history, and the results of other hormone tests, especially your level of follicle stimulating hormone (FSH).
- High LH in adults: But high LH levels through the month may mean your ovaries aren't working properly. In men, high levels of LH may be caused by: A germ cell tumor (a tumor that starts in the cells that become sperm), Mumps, A physical injury to the testicles, Testicles that never developed normally, A chromosomal disorder, such as Klinefelter syndrome. Limitation: In women who have menstrual periods, LH levels change through the month. An increase in LH a couple of weeks after your period usually means you're ovulating normally. Next step: Your provider can explain what the results of your LH test mean.
- Low LH in adults: Lower-than-normal levels of LH in adults are often a sign of a problem with the pituitary gland or hypothalamus. Limitation: In women, low LH and FSH levels with missed periods may also be linked to extreme exercise, malnutrition, stress, or being very underweight. Next step: Your provider can explain what the results of your LH test mean.
- LH levels naturally vary throughout the menstrual cycle in women who menstruate.
- Results must be interpreted alongside other hormone tests (FSH, estrogen, testosterone, progesterone) and your medical history.
- At-home urine ovulation tests are screening tools and do not diagnose any condition.
What to do next
Your provider can explain what the results of your LH test mean.
- Why is my healthcare provider ordering this LH test?
- What do my LH results mean along with my other hormone test results?
- Do I need any follow-up tests based on these results?
Evidence source
Source: U.S. National Library of Medicine (MedlinePlus). Practices and reference ranges may differ in your country.
U.S. National Library of Medicine: Luteinizing Hormone (LH) Levels Test