Luteinizing Hormone (LH) in Serum or Plasma
This test measures the amount of luteinizing hormone (LH) in your blood. LH is a hormone produced by the pituitary gland that plays a key role in reproductive health, particularly in regulating ovulation in women and sperm production in men.
["LH helps trigger ovulation and supports hormone balance for fertility."]
Key facts at a glance
- LOINC
- 34434-1
- Short code
- LH/FSH SerPl-Rto
- Synonyms
- LH/FSH SerPl-Rto
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 1.5
- Ref high
- 9
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 83002
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
Why Is This Test Done?
Doctors may order an LH test to evaluate reproductive health, diagnose hormonal imbalances, or assess conditions like polycystic ovary syndrome (PCOS), infertility, or menopause. It can also help monitor treatment for hormone-related disorders.
Who Might Need This Test?
Women may need an LH test if they experience irregular periods, trouble getting pregnant, or symptoms of hormonal changes. Men might have it if they have low sperm counts or fertility concerns. Your doctor will determine if this test is appropriate for your situation.
What to Expect Before the Test
No special preparation is usually needed, but your doctor may advise avoiding certain medications or activities that could affect hormone levels. You may be asked to fast for 8–12 hours before the test if blood is drawn early in the morning for more accurate results.
What Happens During the Test?
A healthcare provider will draw blood from a vein in your arm. You may feel a slight pinch, but the process is quick and usually painless. The blood sample is then sent to a lab for analysis.
Reference range
Follicular: 1.5-9.0 mIU/mLN/A
For females: inform if menstrual cycle status. For certain tests, timing within menstrual cycle may matter.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
What Does This Test Measure?
Short name
LH Test
Frequently asked questions
The test measures the concentration of LH in your blood, typically using an immunoassay method to detect and quantify the hormone.
How Are LH Levels Interpreted?
What Are Common Reasons for Abnormal LH Levels?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy