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Luteinizing Hormone (LH) – Serum, Quantitative Immunoassay

Published: August 9, 2026Updated: August 16, 2026

This test measures the amount of luteinizing hormone in your blood. LH is a hormone produced by the pituitary gland that plays a key role in reproductive health, including ovulation in women and sperm production in men.

Quick summary

["LH helps regulate important reproductive functions and may be checked for fertility issues or hormonal imbalances."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
27885-3
Short code
LH 1.5h p chal SerPl-aCnc
Synonyms
LH 1.5h p chal 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 This Test Might Be Ordered

Your healthcare provider may recommend this test if you have symptoms like irregular menstrual periods, infertility, or signs of hormonal disorders. It could also be part of routine screening for conditions affecting reproductive health, such as polycystic ovary syndrome (PCOS) or thyroid disorders.

What to Expect Before the Test

No special preparation is needed for this blood test. You may be asked to fast for 8–12 hours before the draw if your provider specifies it, but LH levels are generally stable regardless of fasting.

What the Test Results Mean

Results are interpreted based on your age, sex, and medical history. High LH levels might indicate conditions like PCOS or premature ovarian insufficiency, while very low levels could suggest pituitary disorders or certain medications affecting hormone production.

Common Reasons for Testing

LH testing is often used to evaluate fertility, diagnose hormonal imbalances, or monitor conditions like menopause, pituitary tumors, or thyroid disorders.

Reference range

Follicular: 1.5-9.0 mIU/mLN/A

Specimen: serum

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.

Clinical Significance: LH’s Role in Health

Short name

Luteinizing Hormone (LH) Test

Frequently asked questions

What does a high LH level mean?
A high LH level may signal conditions such as premature ovarian insufficiency (POI), polycystic ovary syndrome (PCOS), or certain pituitary disorders. In men, elevated LH can sometimes indicate low testosterone levels or other hormonal imbalances.
What does a low LH level mean?
Low LH levels can occur with pituitary tumors, hypothyroidism, or conditions affecting the hypothalamus. In women, very low LH may suggest ovarian dysfunction or certain genetic disorders. In men, it could indicate hypogonadism or other reproductive system issues.
How often should I get this test?
The frequency depends on your symptoms, medical history, and why the test was ordered. Your healthcare provider will determine the best schedule based on your individual needs, such as monitoring fertility treatments or managing a diagnosed condition.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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