What Is a Luteinizing Hormone Surge?

A luteinizing hormone (LH) surge is a spike in the levels of luteinizing hormone that precedes ovulation in women and testosterone formation in men. It is possible to identify this hormone in the blood and urine to learn more about a patient's fertility status. Unusually high or low levels can indicate a problem that might lead to infertility and other health issues. Home monitoring kits are available for patients who want to identify a luteinizing hormone surge as part of a fertility awareness plan.

The pituitary gland is responsible for producing this hormone. Hormone levels rise and fall cyclically in the human body in response to environmental pressures as well as preset patterns. This hormone plays a critical role in ovulation and subsequent fertility. In women, a luteinizing hormone surge typically occurs about 24 hours before ovulation. It triggers a cascade of reactions inside the body, all of which play a role in the patient's fertility.

Patients who are using at-home fertility awareness to conceive can take regular urine samples to learn about the timing of their cycles, and they might target pregnancy attempts for the period around the luteinizing hormone surge for the best chance of success. It is important for people to be aware that women are fertile shortly before ovulation as well, so this technique is not reliable for couples who want to avoid pregnancy, because by the time the luteinizing hormone surge occurs, the patient is already fertile.

If a patient cannot get pregnant after about a year of attempts, infertility might be an issue. A doctor can recommend a series of tests for the patient and her partner to determine whether either of them has an underlying medical condition that might be contributing to the problem. Sometimes the issue is a mild issue that might be easily correctable. Unusual hormone levels also might be indicative of a more serious problem with the endocrine system.

Several blood tests might be necessary to spot a luteinizing hormone surge and determine the patient's baseline levels as well as the level when hormones start to spike. In men, a lack of luteinizing hormone can result in decreased testosterone production. This in turn can lead to infertility as well as other issues, such as the lack of full sexual development and low libido. Men who have concerns about their hormone levels can meet with an endocrinologist to discuss testing and treatment options. Hormone therapy to raise testosterone levels might be possible.