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LDL Cholesterol, Serum/Plasma — Mass Concentration

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

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

Quick summary

["LDL cholesterol helps estimate the buildup of fatty plaque in your arteries and your risk of heart attack or stroke."]

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

Key facts at a glance

LOINC
43392-0
Short code
LDL1 SerPl-mCnc
Synonyms
LDL1 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 LDL cholesterol in serum or plasma. LDL is a type of cholesterol that can collect in artery walls, contributing to atherosclerosis and cardiovascular disease.

Why might I need this test?

Your clinician may order this test as part of a cholesterol screening or follow-up, especially if you have high blood pressure, diabetes, heart disease, or a family history of early heart disease.

How is the test performed?

A blood sample is drawn from a vein and analyzed in the laboratory. LDL cholesterol may be measured directly or calculated from the results of other cholesterol tests, depending on the laboratory.

How do I prepare for the test?

You may be asked to fast for about 9 to 12 hours before the test, which usually means no food or drinks other than water. Follow your clinician’s instructions, and tell the laboratory if you have recently taken a cholesterol-lowering medicine.

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?
Often called “bad” cholesterol, LDL carries cholesterol from the liver to body tissues and can contribute to plaque buildup in arteries.
Does LDL cholesterol have to be completely normal?
The target depends on your overall cardiovascular risk and other health conditions. Your clinician interprets the result alongside HDL cholesterol, triglycerides and your medical history.
Can eating affect my LDL cholesterol result?
Yes. A recent high-fat meal can affect cholesterol measurements, which is why fasting may be requested. If you were not asked to fast, ask the laboratory whether the result should be interpreted differently.
  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