With the release of new guidelines for treating and managing cholesterol, there may be questions not only about the changes in the update but about cholesterol itself.

Most people know that high cholesterol is bad. But there’s a bigger picture involved when determining what’s considered too high. Put another way, the same number could be in the normal range for one person but considered high for another.

The only way to know your cholesterol situation and, more importantly, what to do about it, is by working with a health care provider. This is important because poorly managed cholesterol could lead to heart attack, stroke and other major health problems.

Here are the basics needed to understand, treat and manage cholesterol.

What is cholesterol?

“First of all, it’s important for people to understand that cholesterol is itself not a bad thing,” said Dr. Robert Eckel, director of the Lipid Clinic at the University of Colorado Hospital. “Cholesterol is an important part of the body that every cell has on its surface. But in our bloodstream, we don’t want too much and the vehicle that carries it can be important.”

Cholesterol is a waxy substance the body uses to build cells. The liver makes all the cholesterol the body needs. However, dietary cholesterol the kind from food and some drinks such as milk causes the liver to send even more cholesterol into the bloodstream.

Cholesterol is carried in the blood in the form of high-density lipoproteins (HDL)—the “good” kind—and low-density lipoproteins (LDL)—the “bad” kind. And that’s where treatment is emphasized.

The bad kind of cholesterol can collect in the artery walls, eventually causing stiffness and narrowing. This is atherosclerosis, which can be the basis of a heart attack or stroke.

Good cholesterol helps by removing the bad, although that’s not easy to do. HDL can only help in the fight, not win it.

“HDL is not something we try to alter with medication. It’s important in predicting risk but changing it is best done via lifestyle changes,” said Eckel, who was part of the team that created cholesterol guidelines from the American Heart Association, American College of Cardiology and other health organizations in 2013. Those guidelines were updated Saturday.

The total cholesterol figure is based on HDL, LDL and a third factor: triglycerides. Triglycerides not only circulate in blood but are the most common type of fat in the body. A high triglyceride level combined with high LDL or low HDL cholesterol is linked to those fatty buildups within the artery walls that increase the risk of heart attack and stroke.

What do cholesterol numbers mean?

Cholesterol numbers mean different things for each person’s situation.

“There are a lot of factors that enter into the determination of the best level for each individual. For instance, someone in their 40s and 50s the LDL cholesterol may be slightly elevated, but the person might have no other risk factors,” Eckel said.

Dr. Scott M. Grundy, chairman of the writing committee for the new cholesterol guidelines, notes that when doctors are working out an action plan with their patients, they should consider a person’s “risk-enhancing factors” such as family history, kidney disease or other personal scenarios.

“These are important,” said Grundy, a professor of internal medicine at the University of Texas Southwestern Medical Center and Veterans Affairs Medical Center in Dallas. “Patients should be aware of these and work to determine how to think about them with their doctor.”

How is elevated or high cholesterol treated?

Treatment comes in two forms: lifestyle changes and medication.

“We always want people to start with making lifestyle changes,” Eckel said. “That means eating a diet low in saturated fat and trans fats, and enriched with fruits and vegetables, whole grains, legumes, lean meat, fish and nuts. Another lifestyle change is being physically more active.”

If that sounds like a plan for losing excess weight and keeping it off, that’s exactly the point. A healthy body weight helps reduce LDL levels and helps people with normal cholesterol levels stay that way.

Sometimes, diet and exercise alone are enough to get numbers into the comfort zone. Sometimes, they’re not. For those people, the next option is usually taking a cholesterol-lowering medication called a statin.

“This is a very well-proven, evidence-based option,” Eckel said. “A lot of clinical trials strongly support taking statins.”

The type of statin and dose can vary from person to person. In some cases, doctors may prescribe other or additional medications that are not statins, such as ezetimibe or a PCSK9 inhibitor.

“The neat thing about cholesterol-lowering plans is that you can see changes quite quickly,” Eckel said, noting that cholesterol levels can improve within weeks of diet changes or medications.