Skip to content

Luteinizing Hormone (LH) in Serum or Plasma

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

This test measures the amount of luteinizing hormone (LH), a hormone produced by the pituitary gland, in your blood. LH plays a key role in reproductive health, particularly in regulating the menstrual cycle and stimulating ovulation in women, and sperm production in men.

Quick summary

["LH helps manage fertility and hormonal balance."]

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

Key facts at a glance

LOINC
56493-0
Short code
LH 10M p chal SerPl-aCnc
Synonyms
LH 10M 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 Is This Test Done?

Your healthcare provider may order an LH test to check for hormonal imbalances, diagnose fertility issues, evaluate conditions like polycystic ovary syndrome (PCOS), or monitor treatment for hormonal disorders. It can also be used in men to assess issues related to testosterone production or infertility.

What to Expect Before the Test

No special preparation is usually needed, but you may be asked to fast for 8–12 hours before the test if it involves drawing blood from a vein. If you’re taking certain medications, let your provider know. For urine-based LH tests (e.g., ovulation predictor kits), follow the kit instructions carefully.

What Happens During the Test?

A healthcare professional will collect a blood sample from a vein in your arm or, in some cases, provide a urine sample. The sample is then sent to a lab for analysis. Results are typically available within a few days.

What Do the Results Mean?

LH levels vary by gender, age, and life stage. High or low levels may indicate conditions like hormonal disorders, thyroid issues, or reproductive health problems. Your provider will interpret results in the context of your medical history and symptoms.

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.

◆Associated findings1

Short name

LH Test

Frequently asked questions

What Are Common Causes of Abnormal LH Levels?
Abnormally high LH levels may be linked to conditions like early menopause, PCOS, or certain tumors. Low LH levels could signal pituitary disorders, hypogonadism, or issues with the hypothalamus. Always discuss results with your provider for personalized insights.
How Often Should I Get This Test?
Your provider will determine the frequency based on your health needs. Some people get LH tests as part of routine fertility evaluations, while others may need it periodically to monitor treatment progress or symptoms.
Can LH Levels Change with Diet or Exercise?
While diet and exercise can influence overall hormone balance, LH levels are primarily regulated by the brain and reproductive hormones. Stress, sleep, and certain medications may also affect results, so consistency in testing is important.
  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