Lab test
What is LDL cholesterol, and what LDL level is considered healthy?
LDL cholesterol is the "bad" cholesterol that can build up as plaque in artery walls, so it is the main number used to judge heart disease risk on a lipid panel. MedlinePlus lists under 100 mg/dL as healthy for adults; ARUP grades direct LDL of 129 mg/dL or less as desirable. Targets depend on overall risk.
What does the LDL cholesterol test measure?
LDL (low-density lipoprotein) carries cholesterol to cells. Too much LDL can lead to plaque in the arteries (atherosclerosis), raising the risk of heart attack and stroke. MedlinePlus
LDL may be calculated from total cholesterol, HDL and triglycerides, or measured directly. MedlinePlus
Why is the LDL cholesterol test ordered?
- As part of a lipid panel in a routine exam, to estimate heart disease risk. MedlinePlus
- A direct LDL test measures LDL rather than calculating it. ARUP Laboratories
What are typical LDL cholesterol ranges?
Two sources grade LDL differently, which is a good example of why the range on your own report matters. MedlinePlus
Reference ranges differ between laboratories and testing methods, and many also differ by age, sex, pregnancy or the phase of the menstrual cycle. The range printed on your own report is the one that applies to your result, and a clinician interprets it alongside your history.
| Group | Healthy level |
|---|---|
| Adults 20 and older | Less than 100 mg/dL |
| Category | LDL cholesterol |
|---|---|
| Desirable | 129 mg/dL or less (99 or less with coronary heart disease) |
| Borderline | 130 to 159 mg/dL |
| Higher risk | 160 mg/dL or greater |
What can affect LDL cholesterol results?
- Fasting for 9 to 12 hours may be requested before a cholesterol test. MedlinePlus
- Age, family history, lifestyle and other risk factors change what level is considered healthy for a given person. MedlinePlus
When should you talk to a clinician about a LDL cholesterol result?
- Ask your provider what LDL level is right for you; ARUP’s own interpretive notes set lower goals when coronary heart disease is present. ARUP Laboratories
DiscoverMedica explains what a test measures and what named sources publish. It does not interpret individual results; the clinician who ordered your test, or one you choose, does.
Where can you get a LDL cholesterol test?
A clinician can order it as part of routine or follow-up care. Some services also let you order lab tests yourself; check that a service’s panel includes this marker, which laboratory runs it, and who reviews the result with you.
- Function HealthAnnual membership for broad lab panels, drawn at Quest sites or at home.
- Quest HealthOrder individual lab tests from Quest Diagnostics online, without a doctor’s visit.
LDL Cholesterol Test: questions, answered
What is a good LDL cholesterol level?
MedlinePlus lists under 100 mg/dL as healthy for adults. ARUP Laboratories grades a direct LDL of 129 mg/dL or less as desirable, 130 to 159 as borderline and 160 or more as higher risk, with lower goals when heart disease is present. Your clinician sets a target from your overall risk.
What is the difference between calculated and direct LDL?
Most lipid panels calculate LDL from total cholesterol, HDL and triglycerides. A direct LDL test measures it in the sample instead. MedlinePlus notes your report may say "calculated" when LDL was estimated this way. ARUP Laboratories offers a direct LDL test and grades it on its own scale, shown in the table above.
Is LDL the same as ApoB?
No. LDL cholesterol measures the cholesterol carried in LDL particles, while apolipoprotein B counts the main protein on LDL and related particles. ARUP notes that an ApoB of 130 mg/dL or more corresponds to an LDL above 160 mg/dL. Which of these tests you need is a clinician’s decision.
Sources
- MedlinePlus: Cholesterol Levels
- ARUP Laboratories: LDL Cholesterol, Direct (test 0020257)
- ARUP Laboratories: Apolipoprotein B (test 0050029)
Last reviewed October 7, 2026. Every source above was checked on or before that date. Educational information only, not medical advice; it does not replace a conversation with a licensed clinician. DiscoverMedica does not employ clinicians.