What is a Luteinizing Hormone Test?

This blood test measures the level of luteinizing hormone (LH) in your blood. LH plays a vital role in controlling the menstrual cycle and ovulation by triggering the release of an egg from the ovary. Abnormal LH levels can indicate issues with ovulation, hormonal imbalances, or underlying health conditions.

The test requires a finger prick blood sample that you can easily take from home. Your sample will then be examined by a certified laboratory and you will receive the results within a matter of days. It couldn’t be easier!

What is Luteinizing Hormone?

Luteinizing Hormone (LH) is a hormone produced in the pituitary gland of men and women. In women, LH is responsible for stimulating the ovaries to release an egg around the middle of the menstrual cycle, also known as ovulation. If fertilization occurs, LH also stimulates the production of other hormones to sustain the pregnancy.

Both too high and low levels of LH can stop ovulation, causing irregular periods or a lack of period altogether. High LH is also linked to polycystic ovary syndrome (PCOS), and may be tested along with other hormones in the process of making a PCOS diagnosis.

What do the results of this test mean?

This test measures the level of follicle stimulating hormone in your blood. The results of this test can indicate hormone imbalances that may impact fertility, cause unpleasant symptoms, or indicate a medical condition that affects the production of hormones. 

It is important to note that hormone values alone are not enough to predict the chance of pregnancy. Other factors, such as the quality of the egg cells, fallopian tubes, or the partner’s sperm, are also important. If you have questions about your test results or overall fertility, it is best to consult a doctor for comprehensive advice.

For whom is this test applicable? 

• You have ovaries 
• You are not using hormonal birth-control at this moment (or within the past three months)
• You want to get a better understanding of your hormone levels, risk of hormone-related health conditions, or your fertility

Symptoms of high LH

Symptoms of high LH in women usually mimic menopause, and can include:

• Irregular menstrual cycle
• Hot flashes
• Mood changes, including anxiety, irritability, or depression
• Fatigue
• Sleep disturbances
• Vaginal dryness

Symptoms of low LH

• Irregular menstrual cycle
• Low libido
• Hot flashes
• Difficulty producing milk (if breastfeeding)

Causes of high LH

Higher levels of LH can be a a sign of a condition that prevents the ovaries from making normal levels of sex hormones.

Conditions linked to high LH levels in women include:

• Polycystic ovary syndrome (PCOS)
• Primary ovarian insufficiency (POI)
• Menopause or perimenopause
• Damage to the ovaries from an autoimmune condition, chemotherapy, or radiation therapy
• Adrenal gland disorders
• Turner Syndrome

Causes of low LH

Low LH levels can signify that the pituitary gland in the brain isn’t making the LH needed to support sexual development or reproduction. It can also be related to:

• Kallmann syndrome
• Excessive exercise