Demystifying Cholesterol: The Good, the Bad, and the Rest

We hear a lot about cholesterol, especially the “bad” kind—but what does that mean exactly? How can cholesterol be both good and bad? And more importantly, how do you know if your cholesterol levels are good (or bad)?

Suffice it to say: cholesterol can be confusing, but it doesn’t have to be. Read on as we break down what you need to know about cholesterol—the good, the bad, and the rest.

What Is Cholesterol?

Cholesterol is a waxy, fatty substance found in every cell of your body. You actually need cholesterol to survive, as your body uses it to make hormones, build cell membranes, and produce vitamin D. 

But here’s the thing: your liver already makes all the cholesterol your body needs. That means any extra cholesterol you consume through your diet—through animal-based foods like meat, dairy, eggs, and poultry—can lead to an excess of cholesterol in your blood, especially if you have other risk factors for high cholesterol, such as diabetes or a sedentary lifestyle.

Left unaddressed, high cholesterol can start to accumulate on the walls of your arteries, where it can calcify into plaques and limit the blood flow. Over time, this can develop into a condition known as atherosclerotic cardiovascular disease (ASCVD) and increase your risk of heart attack or stroke.

“High cholesterol means that the amount of fat in the blood is higher than we want it to be,” says Kyauna Sanders, MD, a physician based in New Jersey who is board certified in Internal Medicine. “If it stays high, there can be consequences later.”

What Are the Different Types of Cholesterol?

When your provider runs a cholesterol test (typically called a lipid panel), the results will include four main measures of your cholesterol. These include:

• LDL (low-density lipoprotein): This is the “bad” cholesterol, known for spreading cholesterol throughout your arteries and tissues, where it can build up and restrict blood flow. Studies have linked higher LDL levels to an increased risk of coronary heart disease and heart failure.
• HDL (high-density lipoprotein): This is the “good” cholesterol, so-called because it regulates your cholesterol levels by removing excess cholesterol from your bloodstream and sending it to your liver to get rid of it. Unlike LDL, higher HDL levels are associated with a lower risk of cardiovascular disease and may actually protect against heart disease and death.
• Triglycerides: Triglycerides are a type of fat in your blood. Eating too many carbs, sugar, alcohol, or saturated fats from animal foods can increase triglycerides. Having insulin resistance or diabetes can also increase triglycerides. Like LDL, triglycerides have also been linked to an increased risk of heart disease.
• Total cholesterol: This is a measure of all the cholesterol in your blood. Technically, it includes your LDL and HDL added together, plus 20% of your triglycerides.

Cholesterol Levels: What’s Normal?

Cholesterol levels are measured in milligrams per deciliter (mg/dL). Here are general target ranges for healthy adults aged 20 or older:

Overall, the goal is to have higher HDL and lower LDL, with a total cholesterol below 200 mg/dL.

Cholesterol Levels: What’s High?

Technically, if your total cholesterol is 240 mg/dL or higher, you have high cholesterol. But, to aid in treatment, healthcare providers will also tell you if any of your results are “borderline high” or “above optimal” so you can start making lifestyle changes to lower them. Here’s a breakdown:

You may have noticed that HDL didn’t show up in the chart above. That’s because as the “good” type of cholesterol, your HDL can never be too high. But, it can be too low. Low HDL is defined as 40 mg/dL or lower.

Why Is It Important to Know Your Cholesterol Levels?

Having higher-than-ideal cholesterol isn’t uncommon. About one in eight American adults have elevated total cholesterol levels. Elevated LDL levels are even more common, affecting one in three adults. But, recent research suggests that around one in four adults aren’t even aware that their LDL is high, which means they also aren’t getting it treated. That’s where regular cholesterol screening comes in. 

A cholesterol test is your first step to getting insights into any cholesterol-related issues, says Dr. Sanders, including atherosclerotic disease and metabolic syndrome. “It gives a bigger picture of your overall risk. It can also help with setting goals for preventative things like diet and exercise. Knowing your cholesterol can let you know if you need to look into anything further. For example, ‘Am I eating healthy foods? Am I eating lower saturated fats?’”

If you don’t know your cholesterol levels, you don’t know whether you need to make any changes to lower it. Usually, high cholesterol is a chronic, progressive disease that gets worse with time, unless you make lifestyle changes or take medication to address it. 

High total cholesterol, LDL, and triglycerides can all increase your risk of heart disease and death, while high HDL can protect against it. For example, a meta-analysis that summarized 14 separate studies found that people with high cholesterol were 27% more likely to die from a cardiovascular event such as heart attack or stroke, while those with higher levels of HDL were 40% less likely.

Cardiovascular disease is the world’s leading cause of death, representing 31% of all deaths worldwide. With some of the risk factors, like age and genetics, there’s not much you can do. But you can modify your cholesterol. 

Most people with high cholesterol don’t present any symptoms, so getting a cholesterol test is your best way to know where you stand.

How Often Should I Get My Cholesterol Checked?

In general, healthy adults should get their cholesterol checked every 5 years, starting at age 35 for men and age 45 for women. If you have any cardiovascular risk factors, you should get screened sooner, starting at age 25 for men and age 30–35 for women. To recap:

As you age, your healthcare provider will re-calculate your 10-year risk of developing cardiovascular disease, and may encourage you to get tested more frequently depending on the results. If you have a family history of high cholesterol, your healthcare provider may recommend getting tested sooner and more regularly. And if you already have high cholesterol or other health conditions that raise your risk, they may want to check you more regularly to ensure your treatment and lifestyle changes are working.

How Can I Lower My Cholesterol?

Treatment for high or borderline high cholesterol usually involves a mix of lifestyle changes and medication.

Lifestyle Changes

“Diet is huge when it comes to lowering cholesterol,” says Dr. Sanders. “It’s the best medicine, honestly.” The #1 dietary recommendation for high cholesterol involves reducing your intake of saturated fats and trans fats. At most, saturated fat should represent 5% to 7% of your dietary intake, or less.

Instead, opt for foods with higher levels of unsaturated fats and fiber, which have been shown to reduce LDL cholesterol. Swapping meat-based protein for plant-based proteins, especially soy, is also a good option, as well as increasing your intake of tomatoes, flaxseed, and almonds. In general, research suggests following a plant-based diet—such as a Mediterranean, vegan, or vegetarian diet—is a more heart-healthy approach.

Exercise is also highly recommended for people with high cholesterol, especially aerobic exercise (think jogging, biking, or dancing). If you can, aim to exercise 3–4 days a week, for at least 40 minutes each time. If you can, increase that to 30 minutes per day, 5–6 days a week.

Excessive drinking and smoking are also associated with higher cholesterol levels, so try to quit or limit how much you drink or smoke. 

Medications

Statins are the main medication for treating high cholesterol. There are a number of these medications available—including more affordable generics—so your healthcare provider can recommend the best one for you based on your cardiovascular risk and medical history. 

If you start statins, your provider may recommend another cholesterol test about two months later to see how well the medication is working.

Do You Know Your Cholesterol Numbers?

High total cholesterol, LDL, and triglycerides can increase your risk of heart disease and death, while high HDL may lower it. 

The only way to know your cholesterol levels is through a blood cholesterol test. Once you get your results, you’ll know what you need to do next: whether that includes keeping up the good work, making a few lifestyle changes, or talking to your provider about statins. And while it only shows a correlation and not a causation, it’s worth noting that a recent 20-year review found that as cholesterol screening increased in the US, cholesterol levels reduced. 

So, if it’s been a while since your last cholesterol test (or you’ve never had one), it might be time to book that check up. In the meantime, follow Dr. Sanders’ recommendations for preventing high cholesterol: adopt a healthy diet low in saturated fats, exercise regularly, and stop smoking.

How K Health Can Help

Do you need to get your cholesterol checked? You can visit a primary care provider online.

With the K Health app, you can check your symptoms, explore conditions and treatments, and if needed, text with a healthcare provider in minutes. 

K Health’s AI-powered app is based on 20 years of clinical data.