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Low-Density Lipoprotein Cholesterol, Serum/Plasma — Substance Concentration

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

A blood test that measures low-density lipoprotein (LDL) cholesterol, a lipoprotein that carries cholesterol in the blood.

Quick summary

["LDL cholesterol is one of the main measures used to assess cardiovascular risk."]

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

Key facts at a glance

LOINC
91116-4
Short code
LDL5c SerPl-sCnc
Synonyms
LDL5c SerPl-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?

Low-density lipoprotein (LDL) cholesterol is a type of blood lipid, or fat, that transports cholesterol to tissues. This test measures the amount of LDL cholesterol in serum or plasma.

Why might I need this test?

LDL cholesterol is commonly measured as part of a lipid panel to help assess the risk of heart attack and stroke. It may also be monitored if you have heart disease, diabetes, high blood pressure, or are receiving treatment to lower cholesterol.

How is the test performed?

A blood sample is drawn from a vein and analyzed by a laboratory. The LDL result may be measured directly or calculated from other cholesterol values, depending on the laboratory method.

How do I prepare for the test?

Fasting is often not required for a routine lipid panel, but follow your clinician's instructions. If fasting is requested, you will usually be asked to avoid food and drinks other than water for 9 to 12 hours beforehand.

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 a high LDL cholesterol level dangerous?
Persistently high LDL cholesterol can contribute to plaque buildup in arteries and increase cardiovascular risk. Your clinician can explain how your result relates to your overall risk and whether treatment may be needed.
Does LDL cholesterol have to be measured directly?
No. Some laboratories measure LDL directly, while others calculate it using total cholesterol, HDL cholesterol, and triglyceride results. The laboratory report indicates which approach was used.
Can I lower LDL cholesterol with lifestyle changes?
For many people, eating a heart-healthy diet, exercising regularly, maintaining a healthy weight, and not smoking can help improve cholesterol levels. Some people also need medication prescribed by their clinician.
  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