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Low-Density Lipoprotein Cholesterol (LDL-C), Serum/Plasma — Substance Concentration

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

Measures LDL cholesterol (LDL-C) in blood to help assess cardiovascular risk. Results may be calculated from other lipids or measured directly.

Quick summary

["LDL cholesterol is a major cardiovascular risk marker, and the result should be interpreted with your other cholesterol levels and health history."]

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

Key facts at a glance

LOINC
91113-1
Short code
LDL2c SerPl-sCnc
Synonyms
LDL2c SerPl-sCnc
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 test measures low-density lipoprotein cholesterol (LDL-C), often called “bad cholesterol,” in serum or plasma. LDL-C is a major factor in the development of cholesterol buildup in arteries.

Why might I need this test?

An LDL-C test is commonly used to assess cardiovascular risk, monitor cholesterol-lowering treatment, or evaluate people with a personal or family history of heart disease, stroke, or high cholesterol.

How is the test performed?

A blood sample is drawn and analyzed for LDL cholesterol. Some laboratories calculate LDL-C from total cholesterol, HDL cholesterol, and triglycerides, while others measure it directly; the method is not specified by this test code.

How do I prepare for the test?

Fasting is often not required, but you may be asked to fast for 9 to 12 hours if this test is part of a complete lipid panel. Follow your clinician’s instructions and tell the laboratory if you have recently changed medicines or your usual diet.

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 LDL cholesterol the same as “bad cholesterol”?
Yes. LDL-C is commonly called “bad cholesterol” because high levels contribute to cholesterol deposits in artery walls.
Does this test require fasting?
It depends on the laboratory’s instructions and whether it is ordered with a complete lipid panel. Fasting for 9 to 12 hours is commonly requested when triglycerides are also being measured.
What if my result is high?
A high result does not by itself mean you have heart disease. Your clinician can review it with your other cholesterol values, medical history, and risk factors and discuss whether lifestyle changes or treatment are 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