LH - Luteinizing Hormone in Dehradun

What is a LH - Luteinizing Hormone?

LH is the pituitary hormone that triggers ovulation. Through most of the cycle it sits at a modest level, then rises abruptly about 24 to 36 hours before an egg is released, and that surge is the event home ovulation predictor kits detect in urine. In men LH stimulates the testes to produce testosterone, so it plays the same role of pituitary instruction. Its most useful clinical application beyond timing is the LH to FSH ratio. In polycystic ovary syndrome LH is often disproportionately raised relative to FSH, classically around two to one or higher, and while this is neither universal nor diagnostic on its own, it supports the picture alongside irregular cycles, androgen excess and the characteristic ultrasound appearance. A high LH with a high FSH indicates the ovaries or testes have failed and the pituitary is compensating, the pattern of menopause or of testicular failure. A low LH with low sex hormones points instead to the pituitary or hypothalamus as the site of the problem.

Why take this test?

LH is advised as part of the reproductive hormone assessment: difficulty conceiving, irregular or absent periods, suspected polycystic ovary syndrome, and suspected menopause or premature ovarian insufficiency, where it is measured with FSH and estradiol on days two to three of the cycle. It is used to detect the ovulatory surge when timing matters in fertility treatment, though for that purpose serial testing or urine kits are usually more practical than a single blood sample. In men it is measured alongside testosterone and FSH to determine whether low testosterone arises in the testes or in the pituitary, which changes management completely. It is also used in the assessment of delayed or precocious puberty. Give the sample on the cycle day your doctor specifies and tell the laboratory when your period started, since a single value without that context cannot be interpreted.

• Difficulty conceiving, with FSH and estradiol on days two to three
• Irregular or absent periods
• Suspected polycystic ovary syndrome, for the LH to FSH ratio
• Suspected menopause or premature ovarian insufficiency
• Low testosterone in men, to localise the cause
• Delayed or precocious puberty

Normal reference ranges

Ranges are indicative for adults. Your report carries the lab-specific reference range and is reviewed by a LabONE pathologist; always interpret results with your doctor.

FAQs: LH - Luteinizing Hormone in Dehradun