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) in your blood. LH plays an important role in sexual development and fertility. The test is used to help diagnose conditions that cause too much or too little LH, such as infertility, menstrual irregularities, pituitary disorders, and early or delayed puberty in children.
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. If you have menstrual periods, you may need to have your test at a specific time during your menstrual cycle.
blood
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.
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). Your provider can explain what the results of your LH test mean.
- High LH: Higher than normal LH levels in women of childbearing age may indicate a disorder affecting the ovaries, such as primary ovarian insufficiency (POI), polycystic ovary syndrome (PCOS), or Turner syndrome. In men, high LH may be caused by testicular damage, Klinefelter syndrome, or other conditions. Limitation: These patterns are general examples. Your provider will interpret your results based on your individual situation. Next step: Your provider will explain what your results mean and may recommend additional testing or evaluation.
- Low LH: Lower than normal LH levels in adults often suggest a problem with the pituitary gland or hypothalamus. In women, low LH with missed periods may also be linked to extreme exercise, malnutrition, stress, or being very underweight. Limitation: These patterns are general examples. Your provider will interpret your results based on your individual situation. Next step: Your provider will explain what your results mean and may recommend additional testing or evaluation.
- 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 healthcare provider will explain what your LH test results mean in the context of your sex, age, symptoms, medical history, and other hormone test results.
- 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
U.S. National Library of Medicine: Luteinizing Hormone (LH) Levels Test