A lipid screening is a blood test that measures the fats and fat-carrying particles in your blood to estimate your risk of heart disease and stroke. The standard test, often called a lipid panel, reports four numbers: total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides. These values help determine whether fatty buildup in your arteries could become a problem, and they’re a cornerstone of preventive health care starting as early as childhood.
What a Lipid Panel Measures
The test captures four key values, each telling a different part of the story.
Total cholesterol is the sum of all cholesterol circulating in your blood. It gives a broad snapshot but doesn’t distinguish between helpful and harmful types, which is why the other numbers matter.
LDL cholesterol (low-density lipoprotein) is the one most strongly linked to plaque buildup in arteries. It’s sometimes called “bad” cholesterol because high levels drive the fatty deposits that narrow blood vessels over time. LDL isn’t measured directly in a standard panel. Instead, the lab calculates it from your other values.
HDL cholesterol (high-density lipoprotein) works in the opposite direction, helping remove cholesterol from your bloodstream. Higher levels are protective, which is why it’s often called “good” cholesterol.
Triglycerides are a different type of fat entirely. Your body converts excess calories, especially from sugar and alcohol, into triglycerides and stores them in fat cells. Elevated triglycerides independently raise cardiovascular risk and, at very high levels, can trigger inflammation of the pancreas.
Healthy Ranges for Adults and Children
The numbers below are general targets for people without existing heart disease. Your doctor may set stricter goals if you already have cardiovascular disease or multiple risk factors.
Adults Age 20 and Older
- Total cholesterol: below 200 mg/dL is desirable; above 240 mg/dL is considered elevated
- LDL cholesterol: below 100 mg/dL is optimal; above 160 mg/dL is high. For people with existing heart disease, the target drops to below 70 mg/dL
- HDL cholesterol: optimal levels are above 50 mg/dL for men and above 60 mg/dL for women. Below 40 mg/dL in men or 50 mg/dL in women is considered low
- Triglycerides: below 150 mg/dL is normal. Levels of 150 to 199 are mildly elevated, 200 to 499 are moderate, and anything above 500 mg/dL is severe
Children and Teens (Age 19 and Younger)
- Total cholesterol: below 170 mg/dL
- LDL cholesterol: below 110 mg/dL
These thresholds aren’t rigid cutoffs. A total cholesterol of 205 doesn’t automatically mean trouble, but it signals that lifestyle factors deserve attention and that repeat testing should happen sooner rather than later.
When and How Often to Get Screened
Screening timelines depend on your age and risk profile. The American Academy of Pediatrics recommends all children have their cholesterol checked between ages 9 and 11. Children with obesity, diabetes, or a family history of early heart disease or high cholesterol may need screening as early as age 2.
For young adults without known lipid problems, screening starts at age 19 and repeats roughly every five years. That frequency increases with age and with the addition of risk factors like high blood pressure, diabetes, smoking, or a family history of heart disease. Most healthy adults should have their lipid panel checked every four to six years. People with diabetes, existing heart disease, or a family history of high cholesterol typically need testing more often, sometimes annually, to track trends and guide treatment decisions.
Do You Need to Fast?
For years, patients were told to skip food for 9 to 12 hours before a lipid panel. That recommendation has loosened significantly. A joint statement from the European Atherosclerosis Society now recommends non-fasting lipid profiles as the routine approach for most patients. The reasoning is practical: removing the fasting requirement makes it easier for people to actually get tested, and the results are accurate enough for risk assessment in the vast majority of cases.
Non-fasting testing works well for initial screenings, cardiovascular risk assessment, children, elderly patients, people with diabetes (who risk low blood sugar from fasting), and anyone already on stable cholesterol-lowering medication. Fasting may still be requested if your non-fasting triglycerides come back above 440 mg/dL, if you’re being monitored for a known triglyceride disorder, or if your doctor needs additional tests that require a morning fasting sample, like fasting blood glucose.
How Your Results Are Used
Your lipid numbers don’t exist in isolation. For adults between 40 and 79, doctors typically plug your total cholesterol and HDL cholesterol into a risk calculator alongside your age, sex, race, blood pressure, diabetes status, and smoking history. The most widely used version, the Pooled Cohort Equations from the American College of Cardiology and American Heart Association, estimates your percentage chance of a heart attack or stroke over the next 10 years.
That 10-year risk estimate is what drives treatment decisions. Someone with mildly elevated LDL but no other risk factors may simply get guidance on diet and exercise. Someone with the same LDL but high blood pressure and diabetes could have a 10-year risk high enough to warrant cholesterol-lowering medication. The calculator is designed for people with LDL levels between 70 and 189 mg/dL who don’t already have cardiovascular disease. If your LDL is 190 or above, that’s generally high enough to prompt treatment regardless of the calculator.
For reference, the “optimal risk” profile used as a benchmark in the calculator assumes a total cholesterol at or below 170 mg/dL, HDL of 50 or higher, untreated systolic blood pressure at or below 110, no diabetes, and no smoking.
When Additional Markers Are Tested
The standard four-value panel covers most people’s needs, but certain situations call for deeper testing. The most common add-on is apolipoprotein B, a protein found on every LDL particle. Because LDL particles vary in size, two people can have the same LDL cholesterol number but very different numbers of actual particles. ApoB gives a more accurate count of those harmful particles.
Several major cardiology guidelines now recommend measuring apoB when triglycerides are elevated (above 150 to 200 mg/dL, depending on the guideline), or when a patient has diabetes, obesity, or metabolic syndrome. In these situations, standard LDL cholesterol can underestimate risk because the math used to calculate it becomes less reliable when triglycerides are high. ApoB is also needed to diagnose certain inherited lipid disorders, like familial dysbetalipoproteinemia, where cholesterol particles accumulate in unusual ways.
Lipoprotein(a), often written as Lp(a), is another marker your doctor might order. It’s a genetically determined particle that raises cardiovascular risk independently of LDL. Since Lp(a) levels are largely set by your genes and don’t change much over time, a single measurement at some point in adulthood can be informative, particularly if you have a strong family history of early heart disease that isn’t explained by traditional risk factors.
What Affects Your Numbers
Genetics play a large role. Familial hypercholesterolemia, an inherited condition affecting roughly 1 in 250 people, can push LDL well above 190 mg/dL regardless of diet. But for most people, lifestyle factors are the primary lever. Diets high in saturated fat and refined carbohydrates raise LDL and triglycerides. Regular physical activity raises HDL and lowers triglycerides. Excess body weight, particularly around the midsection, tends to worsen all four values. Alcohol has a pronounced effect on triglycerides, and even moderate drinking can push levels into the elevated range in susceptible people.
Certain medications and medical conditions also shift lipid values. Thyroid problems, kidney disease, and some hormonal conditions can raise cholesterol. If your numbers come back unexpectedly high, your doctor may check for these underlying causes before attributing everything to diet and genetics.