LDL Cholesterol, Serum/Plasma — Mass Concentration
Measures LDL (“bad”) cholesterol in blood, usually as part of a lipid panel, to help assess cardiovascular risk.
["LDL cholesterol helps estimate the buildup of cholesterol in artery walls and your risk of heart attack or stroke."]
Key facts at a glance
- LOINC
- 57938-3
- Short code
- LDL5 SerPl-mCnc
- Synonyms
- LDL5 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 cholesterol (LDL-C) in blood. LDL is often called “bad” cholesterol because it can contribute to cholesterol buildup in artery walls.
Why might I need this test?
LDL cholesterol is commonly measured as part of a lipid panel during routine screening or follow-up. It helps clinicians assess cardiovascular risk, especially in people with high blood pressure, diabetes, smoking history, or a family history of heart disease.
How is the test performed?
A blood sample is drawn from a vein and separated into serum or plasma. The laboratory measures LDL cholesterol using an approved biochemical method; some results may be calculated from the other components of a lipid panel.
How do I prepare for the test?
Fasting may be requested, but it is not required for every LDL test. If instructed to fast, avoid food and drinks other than water for the period specified by your clinician, and tell the laboratory if you have recently changed medication or supplements.
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.
An elevated LDL cholesterol result may indicate increased risk of cholesterol-related plaque buildup in the arteries and can occur with an unhealthy diet, certain medical conditions, or some medications. A low result is less common and may occur with certain inherited conditions, severe illness, or medicines that lower cholesterol. The result should be interpreted with the rest of the lipid panel and your overall cardiovascular risk.
Short name
LDL cholesterol (LDL-C)
Frequently asked questions
Does a high LDL cholesterol result mean my arteries are already blocked?
Do I need to fast before this test?
How can I lower LDL cholesterol if it is high?
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