Total cholesterol is the sum of three types of cholesterol circulating in your blood: LDL (low-density lipoprotein), HDL (high-density lipoprotein), and VLDL (very-low-density lipoprotein). When you get a lipid panel, the lab measures most of these individually and combines them into a single number. A desirable total cholesterol is below 200 mg/dL, borderline high falls between 200 and 239 mg/dL, and anything at or above 240 mg/dL is considered high.
The Three Main Components
Each type of cholesterol in your total score is carried through the bloodstream by a different protein shell, called a lipoprotein. These lipoproteins vary in size and density, and they play very different roles in your body.
LDL cholesterol is often called “bad” cholesterol because excess amounts deposit into artery walls and form plaque. It typically makes up the largest portion of your total cholesterol number. LDL particles deliver cholesterol from the liver to cells throughout the body, which need it for normal function. Problems start when there’s more LDL than your cells can use.
HDL cholesterol works in the opposite direction. It picks up excess cholesterol from your tissues and arteries and carries it back to the liver for disposal. Higher HDL levels are generally protective, which is why it’s labeled “good” cholesterol. Unlike the other components, you want this number to be higher rather than lower.
VLDL cholesterol is the third piece. VLDL particles are produced by the liver and are rich in triglycerides (a type of fat). As VLDL circulates, it sheds triglycerides and gradually converts into LDL. Like LDL, elevated VLDL contributes to plaque buildup. Most labs don’t measure VLDL directly. Instead, they estimate it by dividing your triglyceride level by five. So if your triglycerides are 150 mg/dL, your estimated VLDL cholesterol is 30 mg/dL.
How the Numbers Are Calculated
During a standard lipid panel, the lab directly measures your total cholesterol, HDL, and triglycerides. LDL is usually not measured directly. Instead, it’s calculated using a formula developed by William Friedewald: LDL equals total cholesterol minus HDL minus triglycerides divided by five. That “triglycerides divided by five” portion is the VLDL estimate.
Rearranging the same math gives you the total cholesterol equation in reverse: total cholesterol equals LDL plus HDL plus VLDL. This is why your lipid panel results should roughly add up. If your LDL is 130, your HDL is 55, and your VLDL is estimated at 25, your total cholesterol would be around 210 mg/dL.
The Friedewald formula works well for most people, but it loses accuracy when triglycerides are very high (above 400 mg/dL). In those cases, labs may directly measure LDL instead of calculating it.
Non-HDL Cholesterol: A Useful Subtotal
Your doctor may also mention non-HDL cholesterol, which is simply your total cholesterol minus your HDL. This single number captures all the cholesterol carried by particles that can damage arteries, including LDL, VLDL, and smaller remnant particles that don’t show up individually on a standard panel.
Non-HDL cholesterol has emerged as a strong predictor of cardiovascular risk. A large analysis combining 68 studies found it was the best predictor among all cholesterol measures for both heart disease events and strokes. It’s especially useful for people with metabolic syndrome or diabetes, where LDL alone can underestimate risk. Calculating it costs nothing extra since it uses numbers already on your lipid panel.
What About Remnant Cholesterol and Lp(a)?
Beyond the big three, your blood contains smaller amounts of cholesterol in particles called remnants. These are the leftover fragments of VLDL after it has delivered its triglycerides. Remnant cholesterol is partially captured in the VLDL estimate on your lipid panel, but it’s gaining attention as an independent risk factor. A meta-analysis found that each standard-deviation increase in remnant cholesterol levels was associated with a 27% increase in major cardiac events. Some research suggests that high remnant cholesterol with low LDL actually predicts heart risk better than high LDL with low remnants.
Lipoprotein(a), or Lp(a), is another particle worth knowing about. It’s structurally similar to LDL and contributes to heart disease risk, but it is not broken out in a standard lipid panel. A portion of Lp(a) cholesterol does get lumped into your LDL and total cholesterol numbers, though you’d never know how much without a separate Lp(a) test. The National Heart, Lung, and Blood Institute recommends Lp(a) testing for people under 65 who’ve had a heart attack, those with a family history of early heart disease, or those whose LDL hasn’t responded well to statins.
Why Your Body Needs Cholesterol at All
Cholesterol gets treated as a villain, but it’s essential for survival. Every cell membrane in your body uses cholesterol to maintain its structure, keeping cell walls stable yet flexible. Without cholesterol, your cells couldn’t function.
Cholesterol is also the raw material for steroid hormones, including cortisol (your stress-response hormone), aldosterone (which regulates blood pressure through sodium and water balance), and sex hormones like testosterone, estrogen, and progesterone. Your skin uses cholesterol to synthesize vitamin D when exposed to sunlight, and your liver converts cholesterol into bile acids, which are the only way your body can break down and absorb dietary fats. Bile production also serves as the body’s primary route for getting rid of excess cholesterol, since you can’t break cholesterol down any other way.
Fasting vs. Non-Fasting Tests
You may have been told to fast for 9 to 12 hours before a cholesterol test. The main reason is triglycerides, which rise after eating. A study published in Circulation found that total cholesterol, HDL, and directly measured LDL were virtually identical between fasting and non-fasting patients. The only meaningful difference was triglycerides: median levels were about 15 mg/dL higher in people who hadn’t fasted.
Since VLDL and calculated LDL both depend on your triglyceride number, eating before the test can slightly inflate your VLDL estimate and slightly deflate your calculated LDL. Your total cholesterol number itself, however, stays essentially the same whether you fast or not. Many guidelines now accept non-fasting lipid panels for routine screening, reserving fasting tests for situations where precise triglyceride or LDL values matter most.