LDL cholesterol

Blood test · no fasting needed

Also known as: LDL-C, Non-HDL cholesterol, Non-HDL-C

Very high-risk heart or vessel disease
Two or more major events such as a heart attack or stroke, one event plus two or more high-risk features, or chronic kidney disease
LDL below 55 mg/dL; non-HDL below 85 mg/dL
Heart or vessel disease, not very high risk
A past heart attack, stroke, stent, bypass or artery disease in the legs, without the very-high-risk features
LDL below 70 mg/dL; non-HDL below 100 mg/dL
No heart disease, higher risk
10-year heart risk 10% or more; diabetes with other risk factors; or age 40 to 75 with a risk factor and triglycerides 150 to 499
LDL below 70 mg/dL; non-HDL below 100 mg/dL
No heart disease, lower risk
10-year heart risk under 10%, outside the group above, including diabetes without other risk factors
LDL below 100 mg/dL; non-HDL below 130 mg/dL
Calcium found on a heart scan
Coronary calcium without symptoms; the goal tightens as the score rises
LDL below 100, 70 or 55 mg/dL, by calcium score
Very high LDL (190 mg/dL or more)
Severe inherited or other very high cholesterol
LDL below 100, 70 or 55 mg/dL, by other risks and heart disease

Your goal depends on your overall heart risk, which your physician estimates.

Units and reference ranges differ between labs.

Cutoffs: 2026 ACC/AHA Guideline on the Management of Dyslipidemia

LDL cholesterol is the cholesterol carried in LDL particles, the main particles that build plaque in arteries. Non-HDL cholesterol counts the cholesterol in every particle that can clog arteries. Most people do not need to fast for this test.

What it tells you

A standard cholesterol panel measures total cholesterol, HDL and triglycerides. LDL is then calculated with an equation, and non-HDL is total cholesterol minus HDL.
Lowering LDL is the best-proven way to prevent heart attacks and strokes. The benefit tracks how far LDL falls, which is why it works as a treatment goal.
Non-HDL adds the other plaque-building particles to LDL. US guidelines call it a better predictor of heart risk and want it on every report.
LDL measures how much cholesterol the particles carry, not how many there are. ApoB counts the particles, and the two disagree most with high triglycerides or diabetes.
When triglycerides are 150 mg/dL or higher, US guidelines prefer non-HDL or ApoB over LDL.
There is no single healthy number. The goal depends on your overall heart risk, from below 100 down to below 55 mg/dL.

What can throw it off

Fasting matters little. After a normal meal, LDL changes by about 8 mg/dL at most on average.
High triglycerides make the calculated LDL less accurate, especially when LDL is low. Non-HDL needs no equation, so it holds up better.
Labs use different equations to calculate LDL, so compare results from the same lab and method.
Some conditions raise it, including an underactive thyroid, blocked bile flow, kidney disease, diabetes and Cushing syndrome.
Some medicines raise it, including steroids such as prednisone, estrogen, testosterone and related hormones, some antipsychotics and cyclosporine.
Diet and weight changes matter. Saturated or trans fat, weight gain, rapid weight loss and ketosis can raise it.
Pregnancy and the menopausal transition can raise it.
Results taken during sepsis are repeated. Some lab methods read falsely low after high-dose N-acetylcysteine given into a vein.

Evidence

Predicting heart disease

Strong human evidenceCEBM Level 1a

Over 200 studies in more than 2 million people show that LDL causes artery disease. Risk grows with both the level and the years of exposure. In over 300,000 people, non-HDL predicted heart disease at least as well in non-fasting as in fasting samples.

Guiding treatment

Strong human evidenceCEBM Level 1a

In 26 statin trials with about 170,000 people, each 39 mg/dL drop in LDL cut major heart and vessel events by about a fifth. The benefit held even when LDL was already below 77 mg/dL. Other treatments that lower LDL the same way gave a similar benefit per drop.

Calculating LDL accurately

Strong human evidenceCEBM Level 1b

Newer equations beat the older Friedewald formula when checked against reference lab methods. In about 450,000 samples, the Martin/Hopkins equation placed people in the right risk group 92% of the time, against 85%. The gains were largest when LDL was low or triglycerides were high.

Limits

It measures cholesterol, not particle count. With high triglycerides or diabetes, LDL can be at goal while too many particles remain.
It is an estimate. It is least accurate when triglycerides are high and LDL is low, the range where goals for high-risk people sit.
One number means different things for different people. A result at goal for one person can be well above goal for another.
A normal LDL does not cancel a high Lp(a), an inherited particle measured separately.
Advanced particle size tests do not help. US guidelines advise against them for judging risk or starting treatment.

References

Reviewed by Shubham Gupta, MD — Founder & President · November 1, 2026

This page is for education only. It is not medical advice. Decisions about any treatment belong with a physician who knows your history.