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Low-Density Lipoprotein Cholesterol, Fluid — Substance Concentration

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

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

Quick summary

["LDL cholesterol is a major risk factor for heart disease and stroke, and the result is interpreted along with your other cholesterol values and overall health."]

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

Key facts at a glance

LOINC
53133-5
Short code
LDLc Fld-sCnc
Synonyms
LDLc Fld-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 in a blood sample. LDL cholesterol can build up in artery walls, making it an important marker for cardiovascular risk.

Why might I need this test?

Your clinician may order this test to evaluate your risk of heart disease and stroke, monitor cholesterol-lowering treatment, or investigate an abnormal cholesterol result.

How is the test performed?

A blood sample is analyzed in a laboratory. LDL may be calculated from other cholesterol measurements or measured directly, depending on the laboratory method.

How do I prepare for the test?

Follow your clinician’s instructions about fasting. Some LDL tests may be done without fasting, but fasting for the requested period can help standardize the results.

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 result may indicate increased risk of plaque buildup and cardiovascular disease. A lower result generally reflects a more favorable cholesterol pattern, although the result should be interpreted with total cholesterol, HDL cholesterol, triglycerides, and your overall risk factors.

Short name

LDL cholesterol

Frequently asked questions

Is LDL cholesterol the same as “bad” cholesterol?
Yes. LDL is often called “bad” cholesterol because elevated levels can contribute to plaque buildup in arteries.
Do I need to fast before this test?
It depends on the test and your clinician’s instructions. Some LDL measurements can be obtained without fasting, while others are interpreted more reliably when you fast.
What can lower LDL cholesterol?
A heart-healthy diet, regular physical activity, weight management, and not smoking may help. Your clinician can also discuss medication if your LDL level or overall risk warrants treatment.
  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