Luteinizing Hormone (LH) Concentration in Serum or Plasma
This test measures the amount of luteinizing hormone, a hormone produced by the pituitary gland that plays a key role in reproductive health, including ovulation in women and sperm production in men.
["LH helps regulate important reproductive functions and may be checked for fertility issues or hormonal imbalances."]
Key facts at a glance
- LOINC
- 50510-7
- Short code
- LH sp2 SerPl-aCnc
- Synonyms
- LH sp2 SerPl-aCnc
- 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 conditions like polycystic ovary syndrome (PCOS), assess fertility, or monitor hormone-related treatments. It can also help identify issues with the pituitary gland or thyroid.
What Does a High or Low LH Level Mean?
High LH levels might suggest conditions like PCOS, premature ovarian insufficiency, or tumors affecting hormone production. Low LH could indicate pituitary disorders, hypothyroidism, or other hormonal deficiencies.
How Is the Test Performed?
A blood sample is taken from a vein, usually in your arm. The sample is sent to a lab where it is analyzed to measure LH concentration using an immunoassay method.
What Are Common Reasons for Testing?
Common reasons include evaluating irregular menstrual cycles, infertility, unexplained low libido, or symptoms of hormonal imbalances. It may also be used during pregnancy monitoring or before certain surgeries.
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.
◆Associated findings1
Short name
LH (Serum/Plasma)
Frequently asked questions
What should I expect before my LH test?
Does LH testing affect my menstrual cycle?
Yes, LH levels naturally fluctuate with age. In women, LH peaks during ovulation and declines afterward. In men, LH levels remain relatively stable but can vary with health conditions or medications.
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