Derek Burnett
Derek Burnett is a Contributing Writer at Bottom Line Personal, where he writes frequently on health and wellness. He is also a contributing editor with Reader’s Digest magazine.
Given the importance of cholesterol levels for our cardiovascular health, it makes sense to wonder just where the cutoff lies between normal and elevated levels. In contemplating their lab results after a cholesterol test, many people wonder, “Does this number mean my doctor is going to put me on a cholesterol-lowering statin medication?” Unfortunately, assessing cholesterol-related risk, and the decision regarding at which level to initiate therapy, is a bit more complex than just looking at a single number. Different physicians rely on different sets of guidelines for determining when a patient’s cholesterol levels put them at sufficient risk to warrant going on cholesterol-lowering medications.
We’ll start by discussing what things virtually all doctors agree on, and then we’ll explore a few of the main sets of guidelines doctors use. But first, let’s review the different measurements that are generated by a cholesterol test:
Note: These measurements are expressed as “mg/dL,” which stands for “milligrams per deciliter.” In other words, they’re measurements of concentration…mass (milligrams of cholesterol, triglyceride, or lipoprotein) per volume (1 deciliter of blood).
You’d be hard-pressed to find a doctor who didn’t believe that cholesterol levels were an important indicator of cardiovascular risk. Just about all physicians would therefore encourage their patients to get their cholesterol checked regularly. Even children and adolescents should undergo testing, to establish a baseline. Then cholesterol levels can be measured every few years up until early middle age, at which point most doctors will want to see annual or biannual testing. Adults 65 and older should get checked once a year.
Doctors also generally agree that cholesterol-related damage is due to LDL (“bad”) cholesterol. That doesn’t mean it’s the only number they care about, though. LDL, HDL, total cholesterol, triglycerides and other lipid levels figure differently into different sets of guidelines.
The other point of broad consensus is that lipid levels should not be looked at in isolation but rather alongside blood sugar and blood pressure. Taken together, these three factors form a much more complete picture of cardiovascular risk than any one of them alone.
If you’re just looking for a basic rule of thumb when discussing your cholesterol results with your doctor, it doesn’t get any simpler than the widely-accepted cutoffs established by the Centers for Disease Control and Prevention for optimal levels:
This classic set of guidelines categorizes patients in four groups, all based on LDL levels: Very high risk, high risk, moderately high risk, and moderate risk.
Just as with the CDC guidelines, ATP III establishes targets for measures of LDL cholesterol, HDL cholesterol, total cholesterol, and triglycerides. But ATP III breaks down the targets more precisely:
| Low | Medium | High | |
| Women | 50 mg/dL | 50-59 mg/dL | 60 mg/dL or higher |
| Men | 40 mg/dL | 40-50 mg/dL | 60 mg/dL or higher |
These guidelines assess overall cardiovascular risk, with cholesterol comprising one of several factors. ACC/AHA sets different cholesterol targets based upon a calculation of the patient’s overall risk of atherosclerotic cardiovascular disease (ASCVD) in the next 10 years:
| If your 10-year heart attack/stroke risk is… | ..then you’re considered… | ..and the goal should be… |
| > 5% | Low risk | Maintain healthy lifestyle |
| 5->7% | Borderline risk | Moderate-intensity statin therapy |
| 7.5->20% | Intermediate risk | Reduce LDL by 30-49% |
| 20%+ | High risk | Reduce LDL by at least 50% |
These guidelines also include special considerations too detailed for the scope of this article. For example, a patient age 75 or younger who already has ASCVD should undergo high-intensity statin therapy. And an adult under age 75 whose LDL cholesterol level is 190 mg/dL or higher should undergo the maximally tolerated statin therapy. Just be aware that when your doctor is discussing therapy options with you, he or she may be considering a more complex picture than simply whether or not your LDL falls above or below a certain number.
Rather than dwelling on LDL levels alone, many doctors zero in on a simple calculation. They take your total cholesterol and divide it by your HDL cholesterol. For example, if your total cholesterol were 200 and your HDL were 40, your ratio would be 4.
This ratio is a good, broad indicator of cardiovascular risk. It makes sense, right? The greater the portion of your total cholesterol that is comprised of HDL, which helps undo the damage of LDL, the better. A ratio of 3.5 or lower is considered excellent, while a ratio 5 or higher is generally thought to be of concern.
Cholesterol behaves differently in the bodies of men and women. However, adults of either sex should try to keep their total cholesterol below 200 mg/dL. Men generally have lower levels of HDL throughout most of adulthood, but women’s HDL levels tend to drop off after menopause. That means women’s HDL target should be higher than men’s, with men aiming for 40 mg/dL and women 50 mg/dL. This discrepancy also affects the ideal ratio of total cholesterol to HDL for women vs men. Women should try to keep their ratio 4 or lower, while men should keep theirs 5 or lower.
