An LH test measures the level of luteinizing hormone (LH) in your blood-blood-test). LH is made by the pituitary gland, a small gland located underneath the brain, and works closely with another hormone called follicle-stimulating hormone (FSH) to control sexual functions. An LH test is often done along with an FSH test, and these tests are used in different ways depending on whether you are a woman, man, or child-blood-test).

In women, LH tests are most often used to help find the cause of infertility, to help determine if a woman is ovulating, to help diagnose polycystic ovary syndrome (PCOS), and to see if a woman has reached menopause-blood-test). LH levels increase during the middle of a womans menstrual cycle, causing the ovaries to release eggs (ovulation) . If a woman is trying to become pregnant, her doctor might want her to get an LH test several times to pinpoint when her body releases an egg.

In men, LH tests can help diagnose fertility problems, low testosterone, and other problems with the testicles. High levels of LH in the blood are a sign of a problem with the testicles and can be a sign of primary testicular failure. Low levels of LH may be a sign of “secondary ovarian failure,” which means the problem starts with the pituitary gland or hypothalamus (a part of the brain) -blood-test).

During an LH levels test, a healthcare professional will take a blood sample from a vein in your arm using a small needle-blood-test). The test usually takes less than five minutes, and you may feel a little sting when the needle goes in or out. Normal LH numbers depend on a few things, like your sex and age-blood-test). Your doctor will probably have the results in a few days-blood-test).