Low-Density Lipoprotein Cholesterol, Lipid Profile
Measures LDL (“bad”) cholesterol in the blood as part of a lipid profile, helping assess cardiovascular risk.
["LDL cholesterol contributes to plaque buildup in arteries, so its level is an important part of heart-risk assessment."]
Key facts at a glance
- LOINC
- 105516-9
- Short code
- LDLFROMLIPIDPROFILE
- Synonyms
- —
- Category
- lipid
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 0
- Ref high
- 100
- Fasting
- true
- 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 (LDL) cholesterol in your blood. LDL is sometimes called “bad” cholesterol because it can contribute to fatty plaque buildup in artery walls.
Why might I need this test?
LDL cholesterol is usually checked as part of a lipid profile to help estimate your risk of heart attack, stroke, and other cardiovascular problems. Your clinician may also use it to monitor treatment intended to lower cholesterol.
How is the test performed?
A blood sample is drawn and analyzed in a laboratory. On some lipid panels, the LDL result is calculated from the measured levels of other types of cholesterol and triglycerides rather than measured directly.
How do I prepare for the test?
Follow your clinician’s instructions about fasting. Some lipid tests do not require fasting, but eating a high-fat meal beforehand can affect the results. Tell the laboratory if you are pregnant or taking a cholesterol-lowering medication.
Reference range
Optimal: <100 mg/dLN/A
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 increase the risk of plaque buildup and narrowing of the arteries. Risk depends on LDL together with other factors, such as blood pressure, diabetes, smoking, family history, and overall cardiovascular risk. If your result is unexpectedly high or low, your clinician can review the complete lipid profile and the circumstances of the test.
Short name
LDL Cholesterol
Frequently asked questions
Is a higher LDL cholesterol level harmful?
Do I need to fast before this test?
Can medications or supplements affect the result?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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