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

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

This blood test measures low-density lipoprotein (LDL) cholesterol, a form of cholesterol associated with buildup in artery walls.

Quick summary

["LDL cholesterol helps assess cardiovascular risk, with lower levels generally being more favorable."]

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

Key facts at a glance

LOINC
91108-1
Short code
LDL4c SerPl-mCnc
Synonyms
LDL4c 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 test measures the concentration of low-density lipoprotein (LDL) cholesterol in blood. LDL carries cholesterol to body tissues and is commonly evaluated as part of a lipid panel or cardiovascular risk assessment.

Why might I need this test?

LDL cholesterol is measured to help assess the risk of heart attack and stroke. Testing may be recommended during routine screening, when cholesterol levels are being monitored, or when risk factors such as high blood pressure, diabetes, smoking, or a family history of heart disease are present.

How is the test performed?

A blood sample is collected from a vein and analyzed by the laboratory. Some LDL results are calculated from other lipid measurements, such as total cholesterol, HDL cholesterol, and triglycerides, while other laboratories measure LDL directly.

How do I prepare for the test?

Follow your clinician's or laboratory's instructions. Fasting for several hours may be requested when this test is part of a lipid panel, and water is usually the only permitted drink during a fasting period unless otherwise directed.

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?
LDL is often called “bad” cholesterol because excess LDL can contribute to cholesterol buildup in artery walls. It is one of several factors used to estimate cardiovascular risk.
Does this test require fasting?
It depends on the laboratory's instructions and whether other tests are being performed at the same time. Fasting is commonly requested for a standard lipid panel, but the laboratory should provide specific preparation instructions.
Can I lower LDL cholesterol?
Cholesterol levels may improve with a heart-healthy diet, regular physical activity, and avoiding tobacco. Some people also need medication, and a clinician can determine the most appropriate approach based on their overall cardiovascular risk.
  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