What is the Luteinizing Hormone (LH) test for?

The article was professionally consulted with Specialist Doctor I Truong Nghia Binh - Specialist in Obstetrics - Obstetrics and Gynecology - Vinmec Da Nang International General Hospital.

The hormone LH plays an important role in ensuring the functioning of the reproductive system in both men and women. The LH test is often used to assess normal reproductive health or abnormalities related to reproductive function. This article will provide the necessary information about this test.

Luteinizing hormone is a hormone that aids the reproductive system: specifically, the ovaries of women and the testes of men. It is produced in the pituitary gland, and is about the size of a pea located just behind the nose. LH is secreted into the bloodstream by the pituitary gland at different stages of the day. The half-life of Luteinizing hormone is about 50 minutes because the concentration of this hormone is constantly changing.
Luteinizing hormone and FSH are two hormones that regulate and stimulate the functional development of the gonads to work synchronously and rhythmically. In women, Luteinizing hormone stimulates the ovaries to produce estradiol. When LH levels rise mid-cycle, ovulation occurs. In the case of fertilization, this hormone stimulates the corpus luteum to produce progesterone to maintain the pregnancy. In men, Luteinizing hormone stimulates the production of testosterone from the Leydig cells of the testicles. Testosterone stimulates sperm production and creates sex characteristics in men.
Because Luteinizing hormone plays an important role in reproductive function, the LH test will be a tool to help assess reproductive health status in both men and women

The main reasons a doctor may order a Luteinizing hormone (LH) test are:
Suspicion of infertility in women or men Check for gland problems Check your levels of the hormone LH aka follicle-stimulating hormone or FSH Symptoms other than infertility that may prompt your doctor to order a Luteinizing hormone test include:
Amenorrhea or absence of menstruation when it comes to cycle low testosterone levels in men low sex drive men low muscle mass In addition, there are signs that you have a pituitary disorder such as:
Fatigue Decreased unexplained weight loss Loss of appetite Muscle weakness If you are trying to get pregnant your doctor may ask you to do multiple LH tests to determine exactly when your body is ovulation or ovulation. At that time, the concentration of LH in the blood will increase.
Doctors also order LH levels when a boy or girl has not entered puberty as expected, or appears to be entering puberty early. Low LH levels are associated with delayed puberty, and high LH levels are associated with early puberty. Signs of precocious puberty include:
Beginning of menstruation Breast development in girls Pubic hair Growth of penis and testicles

You do not need to do anything to prepare for the test. The medical staff will draw blood and perform tests.
The medical staff will use a needle to inject into a vein in your arm and attach a tube to drain the blood. When enough for the test, remove the needle and apply a gauze pad to the injection site to stop the bleeding.
After the blood is drawn you may feel a sting at the injection site but this sensation should go away soon. The blood draw can also make you dizzy and leave a bruise on your hand but this is quite normal.

For women: test results for high levels of LH in the blood can be a sign of primary ovarian failure. That means the condition has a cause that originates in the ovaries themselves. Low LH levels can be a sign of secondary ovarian failure. And the problem of this cause can start in the pituitary gland or the hypothalamus (part of the brain)
For men: test results for high blood LH levels are indicative of a problem related to testicular. Low LH levels mean the problem is with the pituitary gland or the hypothalamus.
People with high LH levels may experience infertility or be associated with polycystic ovary syndrome in women or produce inappropriate testosterone levels in men. In some conditions, genetic factors such as Turner syndrome or Klinefelter syndrome are also factors that increase LH levels. People with this symptom are often unable to have children.
Low LH levels can also cause infertility in men, because hormone levels are not enough to produce sperm or promote ovulation.
Therefore, LH test is quite important to evaluate reproductive function.

LH test results can be affected by a number of factors such as:
Use of certain hormones such as those containing estrogen and progesterone. These are often found in birth control pills Use medications such as clomiphene, spironolactone, naloxone, and some anticonvulsants Prior use of thyroid imaging, bone, or substance use radiation... within 7 days before the LH test. For timely and accurate diagnosis, thereby giving the most effective treatment, doctors need the support of paraclinical tests. Therefore, testing is an essential step in the process of diagnosis and treatment for patients.
Where is the Luteinizing Hormone (LH) test?
For timely and accurate diagnosis, thereby giving the most effective treatment, doctors need the support of paraclinical tests. Therefore, testing is an essential step in the process of diagnosis and treatment for patients.
In order to effectively operate the testing machine system, to meet the "accurate, timely, objective and reliable" testing services, the Laboratory Department of Vinmec International General Hospital has actively completed Improve personnel organization, technical processes, equipment automation (Automatic biochemical-immunological testing system; Automatic hematology testing system; Automatic blood culture machine, ..), management quality management and infrastructure to achieve five-star service standards.