What Luteinizing Hormone Test Results Could Mean

Corey Whelan
·10 min read

Medically reviewed by Monique Rainford, MD

Hormones are chemicals your body produces that travel through the blood to your organs, muscles, and tissues. Hormones help your body regulate a variety of functions, including:

  • Reproduction

  • Sexual function

  • Growth and development

  • Mood

  • Metabolism

Luteinizing hormone (LH) is an important regulator for puberty, fertility, and sex drive. Too low or too high LH levels can affect adults who have a uterus (womb) or penis. They can also affect children of any sex.

This article will explain what LH is, and how LH levels impact reproductive and sexual health in adults and growth and development in adolescents.

What Is Luteinizing Hormone?

LH is a gonadotropic hormone. It is also called lutropin and interstitial cell-stimulating hormone. LH is produced and released by cells in the anterior lobe of the pituitary gland. The pituitary gland is located at the base of the brain, near the front of the skull.

Like all hormones, even a small amount of LH can have a significant impact on bodily functions. Too much or too little LH can cause medical conditions or concerns to occur.

LH is primarily involved in the function of two organ systems:

Within the Brain and Endocrine System

Luteinizing hormone is part of a neurological pathway, comprising the hypothalamus, pituitary gland, and gonads. Gonads (testes and ovaries) are part of the endocrine system and the reproductive system.

The hypothalamus gland in the brain operates the hormonal system. It sends signals about the production and release of LH to the pituitary gland. The pituitary gland and your endocrine system work together to regulate LH and other hormones. This pathway is sometimes referred to as the hypothalamic-pituitary-gonadal axis.

The endocrine system is made up of organs and hormone-secreting glands. Endocrine glands are located throughout the body. Your endocrine system keeps track of how much LH is in the blood.

Information about LH levels is transmitted between the hypothalamus, pituitary, and gonads. If the hypothalamus gets the message that there isn’t enough LH in your body, it will start the process of manufacturing more. If it gets the message that you have enough LH, it will halt production.

Certain health conditions can skew this communication loop, causing too much or too little LH to be produced.

Reproductive Role

LH supports reproductive function and fertility in people of all sexes.

LH levels start to rise several years before puberty begins. In people with ovaries, LH prompts the ovaries to begin the process of manufacturing estrogen a year or two before puberty begins.

Once puberty has occurred, LH works in conjunction with follicle-stimulating hormone (FSH) to control the menstrual cycle, which includes the release of an egg from an ovary each month (ovulation).

LH levels rise and fall, based on where you are in your menstrual cycle. LH “surges” and is at its highest point just before ovulation occurs. After ovulation, LH helps the body get ready for a potential pregnancy, by promoting the production and secretion of progesterone from the corpus luteum.

The corpus luteum is a temporary structure that produces hormones within the ovary after an egg has been released. If pregnancy doesn't take place, it dissolves. If pregnancy does take place, other hormones take over the task of maintaining progesterone, and LH levels drop.

In people with testes who have not gone through puberty, LH signals the testes to start the process of manufacturing testosterone. The testes contain Leydig cells. LH binds to receptors within Leydig cells, which generates the release of testosterone.

Testosterone is a hormone. Without enough testosterone, the testes cannot produce sperm cells. Testosterone supports sex drive in people of all sexes.

LH levels in people with testes do not have a cycle and don’t fluctuate significantly during the month. However, LH levels rise and testosterone levels fall as people with testes people age.

Risks of Abnormal LH Levels

LH production can be altered by underlying health conditions, such as Kallmann syndrome (a genetic condition affecting hormones). Having too much or not enough LH can impact sexual function, fertility, and puberty.

In Females

In people with ovaries, producing too much or too little LH can cause anovulation (not ovulating) to occur. If you don’t ovulate regularly, it will be harder and take longer for you to become pregnant without medical help.

High LH is associated with certain health conditions such as polycystic ovary syndrome (PCOS) or Turner syndrome (a genetic disorder). Both conditions can compromise fertility and your ability to get pregnant.

Low LH may indicate a problem with the pituitary gland, such as a pituitary tumor. It can also be caused by poor nutritional intake. If you have an eating disorder such as anorexia, low LH may result. Extreme athletes with a too-low body mass index (BMI) may also have low LH levels.

In Males

Too high or too low LH in people with testes can reduce sperm cell production, making it harder to impregnate a partner.

High LH can be caused by Klinefelter's syndrome, a genetic disorder that compromises fertility potential. High LH can also be caused by damage to the testicles by cancer treatments, such as chemotherapy and radiation. Infections or alcohol misuse can also have this effect.

Low LH may indicate problems with the hypothalamus or pituitary gland. Low LH reduces testosterone production. This, in turn, can diminish sexual desire.

In Children

In children, LH naturally starts to rise a few years before puberty starts. High LH levels in very young children may indicate precocious (early) puberty. In some instances, it may indicate the presence of a neurological condition or brain injury.

Abnormally low LH levels may be an early clue that your child has a genetic condition, such as Turner syndrome or Klinefelter's syndrome. Infections, eating disorders, and hormonal imbalances can also cause low LH in children. Too low LH can delay puberty in children of any sex.

When to Take an LH Blood Test

LH blood tests are often used to diagnose infertility in people of any sex in the following ways:

  • If you have been unsuccessfully trying to get pregnant, or your menstrual cycle is irregular, a blood workup that includes LH will be helpful. Your results can help identify hormonal conditions such as PCOS or perimenopause (the stage leading up to menopause).

  • An LH blood test can help uncover genetic conditions that affect fertility in people with testes, such as Klinefelter's syndrome. It can also uncover the underlying cause of a low sex drive.

If you’re concerned that your child is entering puberty too early or too late, talk to their pediatrician. An LH blood test can help you get a diagnosis and figure out the next steps.

LH blood tests are also beneficial for uncovering problems in the central nervous system or a pituitary disorder. If you have unexplained symptoms such as fatigue, muscle weakness, weight loss, and a decreased appetite, your healthcare provider may order this test as part of a workup, although it is not enough to diagnose any disease.

Measuring FSH Levels for More Insights

Follicle-stimulating hormone (FSH) works closely with LH and other hormones to regulate menstruation, and support sperm production.

FSH testing is often done alongside LH level testing. It helps provide information about ovarian function, the beginnings of menopause, and other fertility concerns.

In people with testes, FSH testing can help uncover issues with sperm count. In children, it can be used to diagnose issues with early or late puberty.

LH Results Chart

LH in blood or urine can be used to predict when ovulation will take place. These levels vary from person to person, based on age and other factors, such as underlying health conditions.

Reference ranges can vary from lab to lab, so read your lab report in detail to see if numbers are flagged as low or high. Ask your healthcare provider to interpret the results in light of your age and other factors.

Reference numbers for LH blood levels during the menstrual cycle for people who menstruate are:

  • Follicular phase (starts on day one of your period and ends when ovulation starts): 1.1 to 11.6 milli-international units per milliliter (mIU/mL)

  • Ovulation/mid cycle (starts one to two days before ovulation): 17 to 77 mIU/mL

  • Luteal phase (starts after ovulation and lasts until the first day of your next period): Undetectable to 14.7 mIU/mL

LH levels fluctuate and start to rise during perimenopause and menopause. Along with fluctuations in other hormones, including FSH and estrogen, this marks the reduction and eventually, the end of reproductive potential in people with ovaries. The reference value for LH in postmenopausal people is 11.3 to 39.8 mIU/mL.

For adult males, the reference range is 0.8 to 7.6 mIU/mL.

LH and PCOS Complications

Polycystic ovary syndrome is a common condition in people with ovaries. It is earmarked by hormonal imbalance and reduced fertility.

People with PCOS often have a challenging time getting or staying pregnant. Instead of varying through the menstrual cycle, this condition causes overly high LH levels at all times.

Too much LH stimulates the secretion of testosterone and other androgens (hormones present in all sexes but that are usually higher in people with testes). People with PCOS don’t menstruate or ovulate regularly. Some people with this condition experience rare to no periods at all.

Luckily, infertility treatments ranging from taking oral medications such as Femara (letrozole) or Clomid (clomiphene citrate) to procedures such as in vitro fertilization (IVF) can be highly effective solutions.  

Fertility Advice for Low LH Levels

If low LH is keeping you from getting pregnant, you may be able to increase levels by altering the underlying cause. For some people, this may mean reducing the amount of time you spend exercising, or by gaining weight.

If your healthcare provider suspects that a pituitary issue (such as a tumor) is at the root of the problem, they will recommend diagnostic tests such as magnetic resonance imaging (MRI), as well as treatment to resolve the problem. Most pituitary tumors are benign.

Achieving pregnancy despite having low LH can be achieved with ovulation induction and treatment with hormonal medications, such as human chorionic gonadotropin (HCG) and human menopausal gonadotropin (HMG).

Your fertility specialist may recommend that hormonal therapy be done in conjunction with an assisted reproductive technology treatment, such as intrauterine insemination (IUI) or IVF.

Finding Hormonal Balance

Having irregular hormone levels, including LH, are common. If low LH is reducing your fertility, talk to your healthcare provider. They can recommend you to a specialist, such as a reproductive endocrinologist, who can recommend treatment options. Irregular LH levels can be conquered.

Summary

Luteinizing hormone (LH) is produced in the pituitary gland. It stimulates the onset of puberty, regulates menstruation, and contributes to sex drive. Too low or too high LH can be caused by hormonal disorders, genetic conditions, and other issues. It can often be treated medically or through lifestyle changes.

Frequently Asked Questions

How do you balance LH levels naturally?

If you have high LH due to a condition like PCOS, changing your diet may reduce insulin levels and help to restore hormonal balance.

What are the long-term effects of not ovulating?

Not ovulating can result in a buildup of endometrial tissue (the lining of the uterus). In some instances, this can increase your risk for endometrial cancer. Bringing on a "bleed" by using birth control or other hormone pills such as progestins can reduce your risk.

Does luteinizing hormone stimulate women sexually?

Too low LH can decrease testosterone levels in people of any sex. This can negatively impact sexual desire

Read the original article on Verywell Health.