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The LH test contains 1 test with 1 biomarker.

Brief Description: The Luteinizing Hormone (LH) test is a laboratory test that measures the levels of LH in the blood or urine. LH is a hormone produced by the pituitary gland in the brain. In both men and women, LH plays a crucial role in regulating reproductive function and fertility.

Also Known As: Luteinizing Hormone Test, Lutropin Test, Interstitial Cell Stimulating Hormone Test, ICSH Test

Collection Method: Blood Draw

Specimen Type: Serum

Test Preparation: No preparation required

When is an LH test ordered?

A Luteinizing Hormone test may be ordered in the following situations:

1. Evaluation of Fertility Issues: In women, LH levels rise dramatically just before ovulation, triggering the release of an egg from the ovary. Measuring LH levels helps determine the timing of ovulation and can assist in assessing fertility issues, such as irregular menstrual cycles or difficulty conceiving.

2. Assessment of Puberty Development: In children and adolescents, LH levels are involved in the development of puberty. The test may be ordered if a young individual shows delayed or precocious puberty, helping to evaluate the functioning of the hypothalamic-pituitary-gonadal axis.

3. Monitoring Ovarian Reserve: In assisted reproductive technologies, such as in vitro fertilization (IVF), LH levels can be measured to monitor ovarian response and optimize the timing of procedures, such as egg retrieval.

What does an LH blood test check for?

Luteinizing hormone is a hormone linked to reproduction and the stimulation of ovarian egg release in women, as well as testosterone production in males. This test determines how much luteinizing hormone is present in the blood.

The pituitary gland, a grape-sized structure near the base of the brain, produces LH. The hypothalamus in the brain, the pituitary gland, and the hormones generated by the ovaries and testicles all work together to control LH production.

Several hormones rise and fall in a certain order in premenopausal women's bodies during each menstrual cycle. LH increases ovulation and the generation of other hormones such as estradiol and progesterone during the menstrual cycle.

Each phase of a woman's menstrual cycle lasts roughly 14 days and is separated into follicular and luteal stages. A mid-cycle surge of follicle-stimulating hormone and LH occurs near the end of the follicular phase. Ovulation is triggered by this surge, which results in the rupture of the egg follicle on the ovary and the release of the egg.

The place where the egg follicle ruptured becomes a "corpus luteum" during the luteal phase. The corpus luteum is stimulated to begin generating progesterone by LH release. While FSH and LH levels decrease, progesterone and estradiol levels rise. If the egg is not fertilized, these hormone levels will drop after a few days. Menstruation begins, and then the cycle repeats itself.

Ovarian function declines and eventually quits as a woman matures and approaches menopause. FSH and LH levels rise as a result of this.

LH stimulates the testicles' Leydig cells to create testosterone in men. After adolescence, men's LH levels remain generally steady. A high level of testosterone sends negative feedback to the pituitary gland and hypothalamus, reducing the amount of LH released.

LH levels in newborns and youngsters peak shortly after delivery and then drop to extremely low levels. Levels begin to rise again at the age of 6-8 years, just before puberty and the development of secondary sexual traits.

Lab tests often ordered with an LH test:

When an LH test is ordered, it's often part of a broader evaluation of reproductive health and hormonal balance. Here are some tests commonly ordered alongside it:

1. Follicle-Stimulating Hormone (FSH):

   • Purpose: FSH is another hormone produced by the pituitary gland that works closely with LH to regulate the reproductive processes.
   • Why Is It Ordered: To assess overall pituitary function and reproductive health. In women, the ratio of FSH to LH can be important in diagnosing conditions like polycystic ovary syndrome (PCOS) or ovarian failure.

2. Estradiol:

   • Purpose: The primary form of estrogen in women, playing a key role in the menstrual cycle and fertility.
   • Why Is It Ordered: To evaluate estrogen levels in relation to LH, particularly in assessments of ovarian reserve, menopause, and menstrual irregularities.

3. Testosterone (Total and Free):

   • Purpose: The primary male sex hormone, also present in women in smaller amounts.
   • Why Is It Ordered: To assess testosterone levels, which can influence or be influenced by LH levels. In men, it helps evaluate testicular function, and in women, it can be important in diagnosing conditions like PCOS.

4. Progesterone:

   • Purpose: A hormone that plays a role in the menstrual cycle and pregnancy.
   • Why Is It Ordered: In women, to evaluate the luteal phase of the menstrual cycle and to confirm ovulation.

5. Prolactin:

   • Purpose: A hormone that can affect menstrual function and fertility.
   • Why Is It Ordered: Elevated prolactin levels can interfere with LH and FSH, leading to menstrual irregularities and fertility issues.

6. Sex Hormone Binding Globulin (SHBG):

   • Purpose: SHBG binds to sex hormones in the blood.
   • Why Is It Ordered: To assess the levels of bioavailable hormones, including testosterone and estrogen.

7. Thyroid Function Tests (TSH, Free T3, Free T4):

   • Purpose: To assess thyroid function.
   • Why Is It Ordered: Thyroid disorders can affect menstrual cycles and fertility, influencing LH and FSH levels.

8. 17-Hydroxyprogesterone:

   • Purpose: To measure the level of 17-hydroxyprogesterone, a hormone important in the production of sex steroids.
   • Why Is It Ordered: Particularly in the evaluation of adrenal gland disorders like congenital adrenal hyperplasia, which can affect reproductive hormones.

These tests, when ordered alongside an LH test, provide a comprehensive view of an individual’s reproductive hormonal balance. They are critical in diagnosing and managing conditions related to fertility, menstrual health, and overall endocrine function. The specific combination of tests will depend on the individual’s symptoms, sex, and medical history.

Conditions where an LH test is recommended:

A Luteinizing Hormone test may be required in the following conditions or situations:

1. Infertility: The test is commonly used in the evaluation of infertility in both men and women. It helps determine if ovulation is occurring regularly, assesses the timing of intercourse or assisted reproductive procedures, and provides insights into potential hormonal causes of infertility.

2. Polycystic Ovary Syndrome (PCOS): PCOS is a common hormonal disorder in women characterized by irregular menstrual cycles, excess androgen production, and multiple small ovarian cysts. LH levels may be elevated in women with PCOS, contributing to the diagnosis and management of the condition.

3. Hypogonadism: HypogonadismHypogonadism refers to a condition where the gonads (ovaries in women or testes in men) do not produce sufficient sex hormones. LH levels can help diagnose and monitor hypogonadism by assessing the functioning of the hypothalamic-pituitary-gonadal axis.

How does my health care provider use an LH test?

Health care providers use the results of a Luteinizing Hormone test in the following ways:

1. Evaluation of Ovulation: In women, LH levels rise significantly just before ovulation. Monitoring LH levels can help determine if ovulation is occurring regularly, aiding in the assessment of fertility issues or the timing of assisted reproductive procedures.

2. Diagnosis of Hormonal Disorders: Abnormal LH levels, in combination with other hormone tests, can assist in diagnosing conditions such as PCOS or hypogonadism.

3. Monitoring Hormonal Treatments: For individuals undergoing hormonal treatments, such as ovulation induction or testosterone replacement therapy, regular monitoring of LH levels can help ensure appropriate dosing and treatment effectiveness.

4. Assessment of Puberty Development: In children and adolescents, LH levels play a role in the onset and progression of puberty. The test can help evaluate whether puberty is occurring at the expected age or if there are abnormalities in the hypothalamic-pituitary-gonadal axis.

It's important to note that the interpretation of Luteinizing Hormone test results should be done by qualified health care providers in conjunction with a thorough clinical evaluation, medical history, and other relevant factors. The results of the test are best understood within the broader context of the individual's specific circumstances and symptoms.

What do my LH test results mean?

Women's Health

Primary ovarian failure and secondary ovarian failure can be distinguished using LH and FSH levels.

Primary ovarian failure is characterized by elevated levels of LH and FSH.

Multiple LH tests can be done to detect the surge that precedes ovulation in women who are attempting to conceive. Ovulation has happened when LH levels rise.

Because a woman's ovaries stop working during menopause, her LH levels rise.

Secondary ovarian failure is characterized by low levels of LH and FSH, which indicate a problem with the pituitary or hypothalamus.

Men's Health

LH levels that are too high could suggest primary testicular failure. This can be caused by testicular injury or developmental problems in testicular growth.

Low levels of LH and FSH are detected in secondary testicular failure and reflect a pituitary or hypothalamic issue.

For both men and women

The LH response to GnRH can assist distinguish between secondary and tertiary dysfunction. After determining the baseline level of LH, a dosage of GnRH is administered through injection. The fact that the pituitary responded to the GnRH and that the level of LH increased afterward suggests a hypothalamic problem. A low amount of LH indicates that the pituitary did not respond to GnRH and points to a pituitary illness.

Children's

Precocious puberty is defined as high levels of LH and FSH together with the development of secondary sexual characteristics at an unusually young age in young children. This occurs far more frequently in girls than in boys. This abnormal development is usually caused by a problem with the central nervous system, which can have a variety of causes.

Normal FSH and LH levels with a few indications of puberty could indicate a benign form of precocious puberty with no underlying or discernible reason, or it could simply be a normal variation of puberty. LH and FSH levels can be normal or below what is expected for a child of this age range in delayed puberty. In addition to other tests, the LH response to GnRH test may aid in determining the cause of delayed puberty. Delay in puberty can be caused by a variety of factors.

Most Common Questions About the Luteinizing Hormone test:

Understanding the Luteinizing Hormone Test

What is the Luteinizing Hormone (LH) test?

The LH test is a blood test that measures the level of luteinizing hormone in your body. Luteinizing hormone is a hormone produced by the pituitary gland, located at the base of the brain. It plays a key role in reproductive health for both men and women.

Why is the Luteinizing Hormone test performed?

The LH test is typically performed to evaluate fertility issues, menstrual problems, and pituitary disorders. In women, it can help determine the cause of menstrual irregularities or evaluate ovarian reserve. In men, it can help assess testicular function.

Interpreting Luteinizing Hormone Test Results

What do high levels of Luteinizing Hormone mean in the test results?

High LH levels may indicate various conditions. In women, high LH levels can suggest polycystic ovary syndrome (PCOS) or premature menopause. In men, it could be a sign of testicular failure. In both sexes, it might indicate a pituitary disorder.

What do low levels of Luteinizing Hormone mean in the test results?

Low levels of LH can indicate hypogonadism, where the sex glands produce little or no hormones. In women, this can lead to a lack of menstruation or fertility problems. In men, it may lead to a decrease in testosterone, affecting sperm production and causing issues with sexual function.

Can the results of a Luteinizing Hormone test vary during the menstrual cycle?

Yes, in women, LH levels typically rise and fall during the menstrual cycle, peaking just before ovulation. Thus, the timing of the test in relation to a woman's cycle can significantly affect the results.

Are Luteinizing Hormone test results affected by age?

Yes, LH levels can change with age. For example, women's LH levels generally increase as they approach menopause.

Luteinizing Hormone Test and Reproductive Health

How is the Luteinizing Hormone test used in evaluating infertility?

In women, the LH test can help determine if they're ovulating, which is crucial for conception. In men, the test can indicate if the testes are producing an adequate amount of testosterone necessary for sperm production.

How is the Luteinizing Hormone test used in relation to Polycystic Ovary Syndrome (PCOS)?

Women with PCOS often have higher levels of LH. The LH test can help in diagnosing this condition, alongside other tests and symptoms.

Can the Luteinizing Hormone test be used in men to diagnose low testosterone?

Yes, an LH test can help identify whether low testosterone levels are due to a problem with the testes or a problem with the pituitary gland.

Can the Luteinizing Hormone test be used to predict menopause?

Yes, as women approach menopause, their LH levels generally increase. However, it's just one of several tests used to predict menopause.

Luteinizing Hormone Test and Other Conditions

Can the Luteinizing Hormone test help diagnose pituitary disorders?

Yes, since LH is produced by the pituitary gland, abnormal LH levels can indicate a pituitary disorder, such as a tumor.

Can the Luteinizing Hormone test be used in diagnosing eating disorders?

Abnormal LH levels can sometimes indicate an eating disorder. Severe malnutrition, often seen in conditions like anorexia nervosa, can disrupt hormone production and affect LH levels.

Can the Luteinizing Hormone test be used to monitor treatment of certain conditions?

Yes, for example, if you're being treated for a pituitary disorder or a reproductive issue, your doctor might use the LH test to monitor the effectiveness of the treatment.

Can the Luteinizing Hormone test be used to diagnose Turner Syndrome?

Yes, girls with Turner Syndrome often have high levels of LH. This test can be used as part of the diagnostic process.

Can the Luteinizing Hormone test be used to detect a luteal phase defect?

Yes, LH levels can help determine the length and health of the luteal phase, the part of a woman's menstrual cycle after ovulation and before the start of her period.

Luteinizing Hormone Test and Other Tests

How does the Luteinizing Hormone test relate to the Follicle-Stimulating Hormone (FSH) test?

Both LH and FSH are produced by the pituitary gland and play critical roles in reproduction. Both are often tested together when assessing fertility issues or menstrual problems.

How does the Luteinizing Hormone test relate to the Estradiol test?

Estradiol is a form of estrogen, the primary female sex hormone. Along with LH and FSH, estradiol is often tested when evaluating fertility, menstrual problems, or menopause.

Why might the Luteinizing Hormone test be ordered with a Progesterone test?

In women, progesterone levels rise after ovulation, triggered by an increase in LH. Testing progesterone along with LH can confirm if ovulation has occurred.

How is the Luteinizing Hormone test different from the hCG test?

While both can be used to evaluate reproductive health, they measure different things. The LH test measures luteinizing hormone, which triggers ovulation. The hCG test measures human chorionic gonadotropin, a hormone produced during pregnancy.

Can the Luteinizing Hormone test replace the need for an ultrasound in diagnosing PCOS?

No, while the LH test can suggest PCOS if levels are high, an ultrasound is typically used to visualize the ovaries and confirm the diagnosis.

General Queries

Can medications affect the Luteinizing Hormone test results?

Yes, certain medications, including birth control pills and hormone therapy, can affect LH levels.

Can illnesses or stress affect the Luteinizing Hormone test results?

Yes, acute illness or stress may affect LH levels. If you're sick or stressed at the time of the test, you should inform your healthcare provider.

Can the Luteinizing Hormone test be used to determine the timing of ovulation for family planning?

Yes, a surge in LH typically precedes ovulation by 24-48 hours, and detecting this surge can help predict when ovulation will occur.

We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.