LDL Cholesterol
The cholesterol carried in LDL particles, which can build up in artery walls. It is the main cholesterol number used to estimate heart and blood vessel risk.
AI-verified against cited sources. Awaiting expert reviewAlso called LDL-C, LDL, LDLCLOINC 13457-7
Check your result
Type your result to see where it falls.
Nothing you type here leaves your browser.
What it is
LDL stands for low-density lipoprotein. LDL particles carry cholesterol through your blood. LDL cholesterol (LDL-C) is the amount of cholesterol inside those particles. Too much can slowly build up in artery walls over the years. Most labs work out your LDL from your total cholesterol, HDL cholesterol and triglycerides, and some measure it directly.
Why it matters
LDL cholesterol is one of the best-studied markers for heart and blood vessel disease. In large studies, lower LDL goes with a lower long-term chance of heart attack and stroke, across a wide range of levels. Your clinician reads your LDL together with your age, blood pressure, blood sugar, smoking status and family history, because the right target depends on your overall risk.
If it’s low
A low LDL is usually not a concern. It is often the result of diet, lifestyle or cholesterol-lowering treatment, and heart-health goals aim for lower numbers. Rarely, a very low level without treatment comes from an inherited condition, poor absorption of nutrients or another illness, so a clinician may want to look into it. Calculated LDL can also be less accurate when it is very low.
Common causes
- Cholesterol-lowering treatment, or a diet low in saturated fat
- An overactive thyroid (hyperthyroidism)
- Poor absorption of nutrients (malabsorption) or malnutrition
- Advanced liver disease
- A recent heart attack or other serious illness, which can lower cholesterol for a while
- Rare inherited conditions that cause very low LDL, such as hypobetalipoproteinemia or abetalipoproteinemia
What can help
- If you aren't on cholesterol treatment and your LDL is very low, ask your clinician whether anything else should be checked, such as your liver, thyroid or nutrient absorption
- Ask whether a direct LDL measurement would give a more reliable number
If it’s high
A higher LDL means more cholesterol is traveling in LDL particles. It usually causes no symptoms. Over many years, higher levels are linked to more plaque in the arteries and a higher chance of heart attack and stroke. Many things can raise LDL, and your clinician can put your result in context.
Common causes
- Eating a lot of saturated fat, found in fatty meat, butter, cheese and many baked goods
- Carrying extra weight or being inactive
- Family history and genes. Inherited conditions such as familial hypercholesterolemia can cause very high LDL starting in childhood
- An underactive thyroid (hypothyroidism)
- Poorly controlled diabetes
- Kidney problems such as nephrotic syndrome
- Liver conditions that slow bile flow (cholestasis)
- Heavy alcohol use
- Some medicines
What can help
- Eat more vegetables, fruit, whole grains, beans and nuts, and less saturated fat
- Add soluble fiber, found in oats, beans, lentils and apples
- Get regular physical activity
- If you carry extra weight, losing even 3 to 5 percent of your body weight can improve cholesterol
- Quit smoking and limit alcohol
- Ask your clinician whether your result calls for more than lifestyle changes, and whether thyroid, kidney or other causes are worth checking
Usual ranges
What labs print as the reference range, by who was tested. Ranges differ a little between labs, so the range on your own report is the one your result is judged against.
The usual range depends on age. Choose an age to see the one that applies.
- 20+up to 99 mg/dL
Sources: Labcorp, Mayo Clinic Laboratories, NHLBI, National Institutes of Health, European Heart Journal
Children and teens 1 ranges
- under 20up to 109 mg/dL
Sources: Labcorp, Pediatrics (NHLBI), Mayo Clinic Laboratories
See LDL-C by age and sex, with the U.S. survey numbers where they exist.
Wellness targets
Narrower ranges some clinicians aim for. Being outside one doesn’t mean something is wrong.
up to 69 mg/dL (40–75, diabetes). Evidence: Strong. The ADA Standards of Care (2026) set an LDL-C goal below 70 mg/dL (1.8 mmol/L), graded A, for adults 40 to 75 with diabetes who are at higher heart risk. They set below 55 mg/dL (1.4 mmol/L) for people who also have established heart or artery disease.
NCEP ATP III LDL cholesterol categories (adults)
- Optimalbelow 100 mg/dL
- Near optimal / above optimal100 to under 130 mg/dL
- Borderline high130 to under 160 mg/dL
- High160 to under 190 mg/dL
- Very high190 and above mg/dL
NHLBI Expert Panel LDL-C categories for children and adolescents
- Acceptablebelow 110 mg/dL
- Borderline high110 to under 130 mg/dL
- High130 and above mg/dL
If this applies to you
LDL-C means a little more for some people. Open the one that fits you.
Thyroid condition
NICE lists an underactive thyroid among the common causes of unhealthy cholesterol levels, and suggests a TSH test before cholesterol treatment in people with thyroid symptoms. In trials, changing the levothyroxine dose changed cholesterol levels.
Endurance athlete
Under-fuelling is linked to higher total and LDL cholesterol. The IOC counts total or LDL cholesterol above the lab's range as a secondary sign of REDs.
High cholesterol or heart risk
LDL is the main number cholesterol treatment aims to lower, and the 2026 U.S. guideline sets LDL goals that depend on overall heart risk. It suggests a repeat lipid test 4 to 12 weeks after starting or stepping up cholesterol treatment, to see how well it is working.
Fatty liver or liver condition
Heart disease is one of the most common causes of death in people with fatty liver, and they are about twice as likely to have abnormal blood lipids. AASLD includes a fasting lipid panel in the first workup.
PCOS
The guideline suggests a full lipid profile (cholesterol, LDL, HDL and triglycerides) for everyone with PCOS at the start, at any age or weight. How often to repeat it depends on the results and other heart risk factors.
Prediabetes or diabetes
The ADA suggests a lipid panel when diabetes or prediabetes is first found and yearly after that for people not taking cholesterol medicine. When that medicine is started or changed, it suggests a check 4 to 12 weeks later, then yearly.
Strength training
Anabolic steroids tend to raise LDL cholesterol while lowering HDL. That pattern is linked to artery disease over time.
Perimenopause or menopause
In SWAN, a large U.S. study of women in midlife, total cholesterol, LDL and apoB rose noticeably in the year before and after the final period, and the authors say lipids are worth checking in perimenopause. Estradiol tablets tend to lower LDL and raise HDL, the FDA label notes.
Keto or low-carb eating
LDL responses to low-carb eating vary widely, from large rises to falls. In a meta-analysis of trials, LDL was slightly higher on average than on low-fat diets. An online survey of people who chose to take part, which is weak evidence, found the biggest rises in leaner people with low triglycerides and high HDL.
How common is your level?
NHANES describes the US civilian, non-institutionalized population, not a 'healthy' reference group. People with disease, on medication, fasting or not (except fasting-subsample markers), smokers and so on are all included. A percentile says where a value sits among Americans of that sex and age, not whether it is normal.
Use the left and right arrow keys to read each age. Shift moves five years.
Reference data derived from CDC/NCHS National Health and Nutrition Examination Survey (NHANES), cycles 2015-2016, 2017-March 2020 (pre-pandemic), August 2021-August 2023. Analysis by bloodtesttracker.com; not endorsed by CDC, NCHS or HHS.
Explore LDL-C by age and sex: every percentile as a table, with a download.
What can affect your result
- Diet, especially saturated fat, and body weight
- Physical activity
- Family history and genes
- Thyroid, kidney and liver conditions
- Pregnancy, when cholesterol levels normally rise
- Fasting: a non-fasting LDL is slightly lower than a fasting one
- Method: calculated and directly measured LDL can differ, mostly when triglycerides are high or LDL is low
- A recent heart attack or acute illness, which can lower cholesterol for a while
- Lipoprotein(a), whose cholesterol is counted inside LDL-C
- Calculated LDL (Friedewald) is unreliable when triglycerides are 400 mg/dL (4.5 mmol/L) or higher, and it is less accurate when LDL is very low. Labs then use a newer equation or measure LDL directly.
- Cholesterol carried by lipoprotein(a) is counted inside LDL-C, so a high Lp(a) can make LDL-C look higher than the LDL particles alone would.
- Non-fasting results run slightly lower than fasting results.
- A heart attack or other acute illness can lower cholesterol for a while. Labcorp suggests avoiding routine lipid panels for three months after a heart attack.
- Different direct-LDL assays and equations do not always agree, so compare results from the same method when tracking trends.
About 4 to 12 weeks to show the effect of a change in lifestyle or treatment.
When to talk to a clinician
Talk with a clinician if your LDL is about 190 mg/dL (4.9 mmol/L) or higher, or about 155 mg/dL (4.0 mmol/L) or higher in a child. Levels like these can be linked to an inherited cause that is worth looking into. A result above about 500 mg/dL (13 mmol/L) is rare, and a European lab consensus says it warrants referral to a specialist.
Questions you could ask
- Was my LDL calculated or measured directly, and does that matter for me?
- How often should I have my cholesterol checked?
- What LDL goal makes sense for me, given my other risk factors?
- Should we check for other causes, such as my thyroid or kidneys?
- Would another test, such as apoB or lipoprotein(a), add useful information?
- Could something inherited be involved, given my family history?
Questions people ask
Why can my LDL differ depending on how it was measured?
Most labs calculate LDL from total cholesterol, HDL and triglycerides. That works well for most people, but the math is less accurate when triglycerides are very high or LDL is very low. In those cases a lab may use a newer equation or measure LDL directly. Results from different methods can differ, so it helps to compare results from the same method when you track trends.
Do I need to fast before an LDL test?
Often not. Major guidelines accept non-fasting lipid tests, and non-fasting LDL is only slightly lower than fasting LDL. Your clinician or lab may still ask you to fast if your triglycerides are very high or if other tests need it. Follow the instructions you were given.
What LDL level should I aim for?
It depends on your overall risk, not on one number alone. The older US categories call below 100 mg/dL (about 2.6 mmol/L) optimal. The 2026 US guideline sets goals of below 100, below 70 or below 55 mg/dL depending on how high a person's heart risk is, and European guidelines use similar steps. Evidence: strong for lower goals in people at higher risk, and less direct for people at low risk. Your clinician can tell you which goal fits you.
How do I convert LDL between mg/dL and mmol/L?
Divide mg/dL by 38.67 to get mmol/L, so 100 mg/dL is about 2.6 mmol/L. To go the other way, multiply mmol/L by 38.67, so 3.0 mmol/L is about 116 mg/dL.
Show the science and sources
Units
- 1 mg/dL = 1 mg/dL
- 1 mg/dL = 0.02586 mmol/L
- 1 mg/dL = 0.01 g/L
Is a change real?
LDL-C naturally varies about 8.46% from test to test in the same healthy person. Between two results from the same lab, a change of roughly 24% or more is unlikely to be day-to-day noise or lab variation (95% reference change value). Source: The European Biological Variation Study (EuBIVAS): a summary report.
For clinicians and researchers
LDL-C is the cholesterol content of LDL particles, which carry one apoB-100 each and are cleared mainly by the hepatic LDL receptor. Most labs report a calculated value. The Friedewald equation (TC - HDL-C - TG/5, mg/dL) assumes a fixed VLDL-cholesterol to triglyceride ratio, so it is unreliable at TG of 400 mg/dL or more and less accurate at low LDL-C. The Martin-Hopkins equation uses an adjustable factor, and the Sampson/NIH equation extends accuracy to TG of about 800 mg/dL (Labcorp 'LDL Chol Calc (NIH)' is reported to use it). Direct homogeneous assays and beta-quantification (Mayo LPALD) avoid the TG assumption, but direct assays vary by manufacturer. Cholesterol in Lp(a) is measured within LDL-C; it is roughly 30-45% of Lp(a) mass but varies 6-60% between people, and the EAS does not recommend routine correction except when familial hypercholesterolemia is suspected. LDL-C does not count particles, so apoB or non-HDL-C can disagree with it, most often with high triglycerides, diabetes or low LDL-C. Goals: the 2026 ACC/AHA guideline (as summarized in Life 2026; primary text not accessible) restored risk-based goals of LDL-C below 100 mg/dL (non-HDL-C below 130) for borderline or intermediate 10-year PREVENT risk, below 70 (non-HDL-C below 100) for high risk and for clinical ASCVD that is not very high risk, and below 55 (non-HDL-C below 85) for very-high-risk ASCVD. The 2019 ESC/EAS goals, kept in the 2025 focused update, are below 116 (low risk), below 100 (moderate), below 70 with at least 50% reduction (high) and below 55 with at least 50% reduction (very high). ADA 2026 uses below 70 for adults 40-75 with diabetes at higher risk and below 55 with ASCVD. Severe hypercholesterolemia is LDL-C of 190 mg/dL or more. Fasting is not routinely required (2018 AHA/ACC; EAS/EFLM 2016).
LOINC 13457-7 (primary), 18262-6, 2089-1, 18261-8, 39469-2, 69419-0, 22748-8. Specimen: serum-or-plasma.
Sources
- Low-density Lipoprotein Cholesterol (Direct) (test 120295), Labcorp
- Cholesterol, Low-Density Lipoprotein (LDL), Calculated, Serum (test CLDL1), Mayo Clinic Laboratories
- Lipid Panel, Serum (test LPSC1), Mayo Clinic Laboratories
- Executive Summary of the Third Report of the National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III), NHLBI, National Institutes of Health (2001)
- Expert Panel on Integrated Guidelines for Cardiovascular Health and Risk Reduction in Children and Adolescents: Summary Report, Pediatrics (NHLBI) (2011)
- 2026 ACC/AHA/AACVPR/ABC/ACPM/ADA/AGS/APhA/ASPC/NLA/PCNA Guideline on the Management of Dyslipidemia, American College of Cardiology / American Heart Association (2026)
- The 2026 ACC/AHA Dyslipidemia Guideline: A Critical and Transatlantic Perspective on Personalized Lipid Management, Life (MDPI) (2026)
- 2019 ESC/EAS Guidelines for the management of dyslipidaemias: lipid modification to reduce cardiovascular risk, European Heart Journal (2020)
- 2018 AHA/ACC/AACVPR/AAPA/ABC/ACPM/ADA/AGS/APhA/ASPC/NLA/PCNA Guideline on the Management of Blood Cholesterol, Circulation (2018)
- 10. Cardiovascular Disease and Risk Management: Standards of Care in Diabetes-2026, American Diabetes Association (Diabetes Care) (2026)
- Fasting is not routinely required for determination of a lipid profile: clinical and laboratory implications including flagging at desirable concentration cut-points (EAS and EFLM joint consensus statement), European Heart Journal (2016)
- A New Equation for Calculation of Low-Density Lipoprotein Cholesterol in Patients With Normolipidemia and/or Hypertriglyceridemia, JAMA Cardiology (2020)
- Lipid Panel (test 303756), Labcorp
- Lipoprotein (a) and Low-Density Lipoprotein Cholesterol, Serum (test LPALD), Mayo Clinic Laboratories
- Cholesterol testing, Centers for Disease Control and Prevention
- Blood Cholesterol: Treatment (lifestyle changes), National Heart, Lung, and Blood Institute
- How to Lower Cholesterol with Diet, MedlinePlus (National Library of Medicine)
- Cholesterol (PubChem CID 5997), PubChem, National Library of Medicine
AI-verified against cited sources. Awaiting expert review. Last reviewed 2026-10-03. How we build and check these pages.