LH Blood Test - More Information

The LH test, also known as an LH blood test, lutropin test or luteinizing hormone test, is a lab test that measures the LH blood level.

LH, or luteinizing hormone, is a gonadotropic hormone produced by the pituitary gland. Along with FSH, LH influences the reproductive organs and fertility. In women, LH plays an important role in ovarian maturation and estradiol levels which is why it is often ordered with the estradiol test. LH levels rise into ovulation and this process is thought to be due to a positive feedback mechanism from rising levels of estrogen. As LH levels surge, ovulation is triggered, after which LH levels subsequently drop. Because of this process, LH is used as an indicator that ovulation has occurred - a fertility signal that is essential for anyone attempting to get pregnant. If ovulation results in a pregnancy, the placenta will produce hCG (as measurable through the traditional blood pregnancy test while LH levels remain low.

While elevated LH levels are a normal part of the reproductive cycle, abnormally elevated levels can indicate a variety of things. Most commonly, LH levels, along with high FSH levels, are an indicator of menopause in older women. Abnormally elevated FSH levels in younger women may be an indicator of polycystic ovarian syndrome or various other uncommon conditions.

Luteinizing hormone has a function in men as well. In males, LH works with FSH to help with the manufacture of testosterone in the testicles and associated feedback mechanisms in its production. LH is also thought to be involved with the sex drive in men. Men with low sex drives sometimes get a testosterone test in addition to an LH test for further evaluation.

To get an LH test near you, just place your order online and get your blood drawn at the selected Quest Diagnostics lab. Once you LH lab results are available, you will be notified and can download them electronically. As can be seen on the sample LH lab test report above, the LH blood levels are reported as a number and can be compared against the reference ranges provided for luteinizing hormone by the lab. These LH ranges are typically broken out to account for different states of the menstrual cycle as well as menopause.

The LH test, along with the FSH test, can be ordered together as part of the ovulation test panel.