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

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

Measures LDL (“bad”) cholesterol in blood to help assess cardiovascular risk and guide cholesterol treatment.

Quick summary

["Higher LDL cholesterol generally increases the risk of plaque buildup and heart disease."]

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

Key facts at a glance

LOINC
91106-5
Short code
LDL2c SerPl-mCnc
Synonyms
LDL2c 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?

This blood test measures low-density lipoprotein (LDL) cholesterol. LDL can build up in artery walls, contributing to narrowing and hardening of the arteries.

Why might I need this test?

The test may be used to assess cardiovascular risk, especially if you have high blood pressure, diabetes, smoking history, family history of heart disease, or another risk factor. It also helps monitor the effectiveness of cholesterol-lowering treatment.

How is the test performed?

A blood sample is drawn from a vein, usually from the inside of the elbow. The sample is analyzed in a laboratory to determine the amount of LDL cholesterol.

How do I prepare for the test?

Follow any fasting instructions provided by your clinician. Some lipid tests are more accurate after an overnight fast, while others can be performed without fasting. Continue prescribed medicines unless your clinician tells you otherwise.

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.

A higher LDL cholesterol level can indicate an increased risk of atherosclerotic plaque buildup, which may lead to heart attack, stroke, or peripheral arterial disease. The meaning of the result depends on your overall cardiovascular risk and other conditions. Your clinician can interpret the value alongside HDL cholesterol, triglycerides, blood pressure, and medical history.

Short name

LDL cholesterol

Frequently asked questions

Is LDL cholesterol the same as “bad” cholesterol?
Often, yes. LDL is commonly called “bad” cholesterol because it can contribute to plaque buildup in arteries.
Does a low LDL cholesterol level always mean low cardiovascular risk?
No. Cardiovascular risk also depends on other factors, including blood pressure, diabetes, smoking, family history, and other cholesterol measurements.
Do I need to fast before this test?
It depends on the testing instructions. Your clinician or laboratory should tell you whether an overnight fast is required.
  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