Due to how dangerous and life-threatening heart disease can be, it's fortunate that many of its symptoms alert us when a problem arises that we need to have checked out. Chest pain, inexplicably sweating, leg or arm pain, irregular heartbeat, extreme fatigue and swollen ankles are all signs that indicate something may be awry. 

Such symptoms can be caused by high blood pressure, diabetes or smoking; but another factor that contributes to heart disease is in some ways even more worrisome because it usually brings no such warning signs or symptoms. This subtle condition is high cholesterol − caused by one type of cholesterol in particular.

How many types of cholesterol are there? 

There are two main types of cholesterol in the body: LDL or low-density lipoprotein cholesterol and HDL or high-density lipoprotein cholesterol. Lipoproteins are transporters found in one's blood that the body uses to combine with and transport fats or other lipids to various cells. 

HDL cholesterol is considered "good" cholesterol because it helps rid the body of excess cholesterol and fat by transporting it to the liver to get flushed out of one's system. "Think Pac-Man going through the blood and collecting excess fat to get it out of the body," explains Caroline Susie, RD, a registered dietician and national spokesperson for the Academy of Nutrition and Dietetics.

"Excess" is the key word there because cholesterol is actually a good thing and vital to live. It's getting too much of the wrong type of cholesterol that can cause harm, Susie explains. 

What is LDL cholesterol?

That's where LDL cholesterol, considered "bad" cholesterol, factors in. Too much LDL cholesterol in the body can build up on the walls of one's blood vessels − a formation known as “plaque.” The Centers for Disease Control and Prevention warns that plaque buildup can cause numerous health problems including heart disease and stroke.

Because of the difference between HDL and LDL cholesterol, both need to be checked with a blood test, something the National Heart, Lung, and Blood Institute recommends doing every five years for teenagers and young adults, and more often when adults hit their 40s and 50s. People over 65 should get their cholesterol checked annually.

"When you get your cholesterol levels measured, you’ll likely see three numbers: total cholesterol, HDL cholesterol and LDL cholesterol," explains Jill Weisenberger, MS, RDN, a Virginia-based registered dietician and author of "Prediabetes: A Complete Guide." The total amount includes both HDL and LDL numbers, making each lipoprotein only part of the whole. 

Most adults need to keep their LDL levels below 100 milligrams per deciliter (mg/dL), according to the Cleveland Clinic. An LDL level above that amount increases one's risk of cardiovascular disease.

How to lower LDL cholesterol

Foods with high amounts of saturated fat such as fast foods, baked goods, full-fat dairy or red meat raise one's LDL cholesterol. Because of this, avoiding such foods is important. It's also helpful to include certain foods known to lower LDL levels in one's diet. These include "oats, barley, whole grains, beans, legumes, nuts, vegetables and fatty fish," says Susie.

Tobacco products (including smokeless tobacco and vaping) also have an impact on cholesterol levels. Tobacco lowers one's HDL levels - the "good" type of cholesterol one needs to rid the body of "bad" LDL cholesterol buildup. Because of this, dropping smoking can significantly lower one's LDL levels by keeping HDL levels where they need to be. 

Exercise and weight management are also important since obesity has been shown to raise LDL levels. 

Many medications lower LDL cholesterol as well, but need to be taken as directed to be helpful. "When you use medications to lower cholesterol, you’ll often lower both total and LDL cholesterol even though LDL is the desired target," says Weisenberger. That's why doctors prescribe medication catered to the needs of each patient, including targeting LDL levels specifically. 

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