What is LH (Luteinizing Hormone)? | Dr. Hakan Özörnek

What is LH (Luteinizing Hormone)?

LH (Luteinizing hormone) is a hormone secreted from the anterior pituitary gland in the brain, along with hormones such as FSH, TSH, and PRL. It plays a role in reproductive functions. The release of GnRH (Gonadotropin-releasing hormone) from the hypothalamus stimulates the pituitary gland to release FSH and LH. Gonadotropins refer to FSH and LH.

What is the function of LH?

While FSH plays a role in egg development, LH is the hormone responsible for the rupture of the egg. When LH reaches a high level, known as the LH surge, ovulation has occurred. If fertilization occurs during this period, pregnancy is established. Post-rupture, LH stimulates the production of the Progesterone hormone. LH secreted from the corpus luteum is necessary for the continuation of pregnancy.

What should be the LH value in women?

LH levels vary throughout the menstrual cycle.

Follicular phase (from the beginning of menstruation to ovulation): 1.24-8.62 mIU/ml

Ovulation phase: 19-103 mIU/ml

Luteal phase (after ovulation): 1.3-12.89 mIU/ml

LH values vary according to the reference range of laboratories and hospitals. It is recommended to have your results evaluated by your doctor.

Can LH hormone levels be both low and high?

Since LH values vary according to the phases of the menstrual cycle, high or low values can be detected in the same month depending on when the test is performed.

What should be the FSH on the 3rd day of the menstrual cycle?

Although laboratory reference values vary, FSH on the 3rd day of the menstrual cycle is generally considered normal between 2-12 mIU/ml.

What is the difference between FSH and LH?

Both FSH and LH are hormones secreted from the anterior pituitary gland. FSH begins to rise from the beginning of the cycle, aiding in the growth and maturation of the egg. When the egg reaches sufficient size, LH rises to induce rupture and ovulation.

Why is the LH/FSH ratio important?

The prepubertal ratio, which is 1/1, becomes 1.5-2/1 after puberty. If it is greater than 2.5, possibilities such as polycystic ovary or pituitary tumor are considered.

What does high LH mean?

Mid-cycle elevation of LH is normal as it is necessary for ovulation. However, elevated LH levels at the beginning of the cycle, with values higher than FSH, are most commonly seen as a sign of polycystic ovary syndrome in reproductive-age women. In menopausal women, LH levels also begin to rise.

What are the symptoms of high LH?

High LH in the beginning of the cycle is most commonly observed in polycystic ovary syndrome in reproductive-age women. Symptoms include irregular menstruation, lack of ovulation, tendency to gain weight, and increased hair growth on the face and body.

What is LH deficiency?

LH deficiency is measured on the 2nd-5th day of the cycle and is when the LH level is below 1-1.5 mIU/ml. Conditions such as hypogonadotropic hypogonadism, Kallmann syndrome, high prolactin, eating disorders, excessive weight loss, extreme stress, and certain medications can cause LH deficiency.

How to increase LH?

The condition causing LH deficiency should be evaluated and treated by a doctor.

What is the LH range in menopausal women?

Although laboratory reference ranges vary, LH values during menopause are between 12-55 mIU/ml. Measuring LH alone is not sufficient for diagnosing menopause. FSH, AMH, and E2 hormone levels are more valuable diagnostic tools.

Can pregnancy occur with high FSH levels?

If FSH measured on days 2-3 is greater than 12, it indicates a diminished ovarian reserve. Diagnosis is confirmed by measuring AMH and AFC (antral follicle count). If FSH is higher than 40 and menstruation has not occurred for more than 6 months, a woman cannot conceive. Women with diminished ovarian reserve but still menstruating can still conceive.

What are the LH test prices?

Test prices vary depending on hospitals and laboratories.

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