How Does Luteinizing Hormone Work?
Gonadotropic hormones include LH. Interstitial cell-stimulating hormone and lutropin are other names for it. The anterior lobe of the pituitary gland contains cells that create and secrete LH. The pituitary gland is situated close to the front of the skull, at the base of the brain.
Like all hormones, LH even in little doses can have a big impact on how the body works. Medical illnesses or issues may result from having too much or too little LH.
LH plays a major role in the operation of two organ systems:
Sexually active tissues
the brain and spinal cord
Luteinizing hormone is a component of a neurological route that includes the hypothalamus, pituitary gland, and gonads within the brain and endocrine system. 3 The reproductive system and the endocrine system both include the gonads (testes and ovaries).
The hormonal system is controlled by the hypothalamus gland in the brain. It informs the pituitary gland via signals about the synthesis and release of LH. Your endocrine system and pituitary gland collaborate to control LH and other hormones. The hypothalamic-pituitary-gonadal axis is another name for this circuit.
The organs and glands that produce hormones make up the endocrine system. There are endocrine glands located all over the body. Your endocrine system monitors the level of LH in your blood.
The hypothalamus, pituitary, and gonads communicate information regarding LH levels. In order to make additional LH, the hypothalamus must first receive a signal that there is not enough of it in the body. It will stop producing if it learns that you have adequate LH.
This feedback loop can be thrown off by certain medical problems, which can result in the production of too much or too little LH.
Role in Reproduction
All sexes benefit from LH's assistance for fertility and reproductive health.
Several years before puberty, LH levels start to rise. A year or two before puberty starts, LH signals the ovaries of persons with ovaries to start producing estrogen.
Once a person reaches puberty, LH and follicle-stimulating hormone (FSH) collaborate to regulate the menstrual cycle, which involves the monthly release of an egg from an ovary.
Depending on where you are in your menstrual cycle, LH levels rise and fall. LH "surges" and reaches its peak right before ovulation. By encouraging the production and secretion of progesterone from the corpus luteum after ovulation, LH aids the body in preparing for a prospective pregnancy.
After an egg has been delivered, a transitory organ called the corpus luteum creates hormones in the ovary. If there is no pregnancy, it disappears. In the event of pregnancy, LH levels fall as other hormones take up the role of sustaining progesterone.
LH instructs the testes to begin producing testosterone in those who have testes but have not yet reached puberty. Leydig cells are present in the testes. When LH interacts to receptors inside Leydig cells, testosterone is released.
A hormone is testosterone. The testes cannot create sperm cells if there is not enough testosterone. All sexes' sex drives are supported by testosterone.
In those with testicles, LH levels are constant throughout the month and do not cycle. However, as testicular ageing occurs, LH levels increase and testosterone levels decline
Unusual LH Levels Risks
Underlying medical problems, such as Kallmann syndrome, can impact LH production. 8 Having too much or too little LH can have an influence on puberty, fertility, and sexual function.
For Women
Too much or too little LH production in those with ovaries might result in anovulation, or not ovulating. It will be more difficult and take longer for you to get pregnant naturally if you don't ovulate on a regular basis.
Health issues including Turner syndrome, a hereditary illness, or polycystic ovarian syndrome (PCOS) can lead to high LH levels.
2 Both disorders can make it difficult for you to become pregnant.
Low LH could be an indication of a pituitary disorder, like a tumor. It may also be brought on by inadequate dietary intake. Low LH can happen if you have an eating issue like anorexia. Extreme sportspeople who have too low a body mass index (BMI) may also have low amounts of LH.
For Men
When LH levels are excessively high or low, sperm production is decreased, which makes it more challenging to become pregnant with a partner.
Klinefelter's syndrome, a hereditary condition that impairs reproductive potential, can result in high LH. Damage to the testicles brought on by cancer treatments like chemotherapy and radiation can also result in high LH levels. Alcohol abuse or infections may potentially have this effect.
Low LH could be a sign of pituitary or hypothalamic issues. Production of testosterone is lowered by low LH. In turn, this may cause sexual desire to decline.
For Kids
LH naturally begins to rise in children a few years before puberty begins. Early (precocious) puberty may be indicated by high LH levels in infants. In rare cases, it might be a sign of a neurological disorder or a head injury.
An early sign that your child has a genetic disorder like Turner syndrome or Klinefelter's syndrome may be abnormally low LH levels. Low levels of LH in youngsters can also be brought on by infections, eating problems, and hormonal imbalances. Children of any sex who have too little LH can postpone puberty.
When Should an LH Blood Test Be Performed?
The following methods of diagnosing infertility in people of any sex using LH blood tests: 2
A blood test that includes LH will be beneficial if you have been trying to get pregnant but have been unsuccessful or if your menstrual cycle is unreliable. Your findings may reveal hormonal disorders like PCOS or perimenopause.
An LH blood test can assist identify genetic disorders like Klinefelter's syndrome that have an impact on testicular fertility in individuals. Additionally, it can reveal the root of a low sex drive.
Speak with their paediatrician if you're worried that your child is starting puberty too soon or too late. You can acquire a diagnosis and determine your future steps with the aid of an LH blood test.
A pituitary dysfunction or issues with the central nerve system can be found with LH blood tests. Your doctor may request this test as part of a workup if you experience unexplained symptoms including exhaustion, muscle weakness, weight loss, and decreased appetite, but it is insufficient to make a diagnosis of any condition.
FSH Levels Measured for Additional Insights
To control menstruation and aid in sperm generation, follicle-stimulating hormone (FSH) collaborates closely with luteinizing hormone (LH) and other hormones.
Testing for FSH and LH levels frequently occur together. It contributes to the dissemination of knowledge on ovarian function, the onset of menopause, and other issues related to fertility.
Testing for FSH in test-takers can reveal sperm count problems. It can be used to identify problems with early or late puberty in youngsters.
