LDL Cholesterol, Serum/Plasma — Direct Measurement
A direct measurement of low-density lipoprotein cholesterol in blood, used to help assess cardiovascular risk and guide cholesterol treatment.
["Higher LDL cholesterol can increase the risk of fatty buildup in artery walls and heart disease."]
Key facts at a glance
- LOINC
- 11054-4
- Short code
- LDLc/HDLc SerPl
- Synonyms
- LDLc/HDLc SerPl
- 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 blood test measures LDL (low-density lipoprotein) cholesterol directly. LDL is sometimes called “bad” cholesterol because it can contribute to cholesterol buildup in artery walls.
Why might I need this test?
Clinicians may order this test to assess cardiovascular risk, evaluate high cholesterol, or monitor treatment intended to lower LDL cholesterol. It may also be used when a calculated LDL result is not considered reliable.
How is the test performed?
A blood sample is drawn from a vein and analyzed in the laboratory to measure the amount of LDL cholesterol. No special preparation is required unless your clinician gives you specific instructions.
How do I prepare for the test?
You can usually take this test without fasting. If you are also having other lipid tests, follow any fasting instructions provided by the clinic, and tell the clinician about medicines or supplements that may affect cholesterol results.
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 level may indicate increased cardiovascular risk, particularly when other risk factors such as high blood pressure, diabetes, smoking, or a family history of heart disease are present. A low LDL level is generally less concerning, although very low levels can occur in certain uncommon circumstances. Your clinician will interpret the result alongside your overall health and other cholesterol measurements.
Short name
Direct LDL cholesterol
Frequently asked questions
Is a direct LDL test the same as a standard lipid panel?
Do I need to fast before this test?
What can change my LDL cholesterol?
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