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Low-Density Lipoprotein Cholesterol, Serum/Plasma — Mass Concentration

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

This blood test measures LDL cholesterol, a form of cholesterol that contributes to fatty buildup in artery walls. It is commonly used to help assess cardiovascular risk.

Quick summary

["LDL cholesterol helps estimate your risk of heart disease and stroke, but the result must be considered with other risk factors."]

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

Key facts at a glance

LOINC
46984-1
Short code
LDL2 SerPl-mCnc
Synonyms
LDL2 SerPl-mCnc
Category
lipid
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
0
Ref high
100
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
83721
SNOMED
113079007
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

What is this test?

Low-density lipoprotein (LDL) cholesterol is the main type of cholesterol carried in blood. This test measures the concentration of LDL cholesterol in serum or plasma and is usually part of a lipid panel.

Why might I need this test?

Clinicians use this test to help assess the risk of heart disease, stroke, and circulation problems. It may be ordered during routine screening, when monitoring cholesterol treatment, or when another lipid value is abnormal.

How is the test performed?

A blood sample is drawn and analyzed in a laboratory. LDL cholesterol may be measured directly or calculated from other lipid values such as total cholesterol, HDL cholesterol, and triglycerides; the laboratory report should indicate the method used.

How do I prepare for the test?

Follow your clinician's instructions about fasting. Some lipid tests are performed without fasting, while others request that you avoid food for 9 to 12 hours. Water is generally allowed, and you should not stop prescribed medicines unless instructed to do so.

Reference range

Optimal: <100 mg/dLN/A

Specimen: serum

Fasting for 12-14 hours preferred. Water is permitted. Avoid alcohol for 24 hours before the test.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

LDL cholesterol

Frequently asked questions

Is a high LDL cholesterol level the same as having heart disease?
No. A high LDL level is one risk factor for heart disease, but it does not prove that heart disease is present. Your clinician will interpret it with your medical history and other test results.
Is fasting required for an LDL cholesterol test?
It depends on the test and your clinician's instructions. Nonfasting lipid testing can be useful, but fasting may be requested when results need to be compared with specific standard ranges or when triglycerides are elevated.
Can lifestyle changes lower LDL cholesterol?
Often, yes. Eating more vegetables, fruits, whole grains, and unsaturated fats while limiting saturated and trans fats, exercising regularly, and maintaining a healthy weight may help. Your clinician may also prescribe medication when appropriate.
  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