By: Xavier Van Allen & Caden LaVigne

What are LDL and HDL?

LDL is a low-density lipoprotein that is known as "bad" cholesterol.

HDL is a high-density lipoprotein that is known as "good" cholesterol.

How are LDL and HDL different?

The main structural difference between LDL and HDL is their compositions. Approximately 50 percent of the weight of an LDL particle is cholesterol and only 25 percent is protein. High-density lipoprotein particles, on the other hand, consist of 20 percent cholesterol by weight and 50 percent protein. Since protein is more dense than fat, HDL particles are more dense than LDL particles. The other major structural difference between LDL and HDL is the types of protein they have. Low-density lipoproteins have proteins called B-100 proteins, while HDL particles have mostly A-I and A-II proteins.

Why do doctors check patients' cholesterol?

Doctors check patients cholesterol levels just to make sure their arteries are clear of plaque, and just to make sure their not at risk for any major health issues such as; Heart attacks, stokes, and heart disease. If the patients' doctor finds that their cholesterol levels are too high they will prescribe them medicine to lower their cholesterol level.

What is the big deal about cholesterol?

When too much LDL circulates in the blood, it can slowly build up in the inner walls of the arteries. Together with other substances, it can form plaque, a thick, hard deposit that can build up in the arteries and make it less flexible. This condition is known as atherosclerosis. If a clot forms and blocks a narrowed artery, a heart attack or stroke can result.

High levels of HDL seem to protect against heart attack. Low levels of HDL also increase the risk of heart disease. Medical experts think that HDL tends to carry cholesterol away from the arteries and back to the liver, where it's passed from the body. Some experts believe that HDL removes excess cholesterol from arterial plaque, slowing the LDL buildup.


Triglyceride is a molecule that is monitored when looking at a patient’s blood.

Your body converts triglycerides, a type of fat found in the bloodstream, into cholesterol molecules. High triglyceride levels increase your risk for heart disease. (Cholesterol & Triglycerides Health Center)

What do the numbers mean?

When you go to see your family doctor, he may recommend you to get a cholesterol test. The standard cholesterol test is called a lipoprotein profile. A lipoprotein profile measures three specific kinds of fat.

Low-density lipoproteins (LDL) is the "bad cholesterol," the main cause of plaque build-up, which increases your risk for heart disease. The lower the number, the better your health will be.

High-density lipoproteins (HDL) is the "good cholesterol." It transports bad cholesterol from the blood to the liver, where it is excreted by the body. The higher the number, the better the better your health will be.

Triglycerides is another type of fat in the bloodstream, triglycerides are also linked to heart disease. They are stored in fat cells throughout the body. (Why Do Doctors Monitor the Concentration of LDL & HDL)

Unsaturated, saturated, and trans fat: the good and the bad.

Unsaturated fats can have a positive effect on your health when eaten and when used to replace saturated fats or trans fats. Unsaturated fats can help reduce the LDL levels in your blood and lower your risk of heart disease and stroke.

Solid foods high in saturated fats raises blood cholesterol. Eating foods that contain saturated fats raises the level of cholesterol in your blood. High levels of blood cholesterol increase your risk of heart disease and stroke.

Triglycerides is the scientific name for the main form of fat found in the diet and in the body. You need some triglycerides for good health. Having high triglycerides can raise your risk of heart disease and may be a sign of metabolic syndrome.

The best way, to get the best results!

The main goal of cholesterol-lowering treatment is to lower your LDL level enough to reduce your risk of developing heart disease or having a heart attack. The higher your risk, the lower your LDL goal will be. There are two main ways to lower your cholesterol level.

Therapeutic lifestyle change includes a cholesterol-lowering diet called a TLC diet, physical activity, and weight management. TLC is for anyone whose LDL is above goal.

Drug treatment is used when cholesterol-lowering drugs are needed. They are used together with Therapeutic lifestyle treatment to help lower your LDL. (High Blood Cholesterol: What You Need To Know)

Work Cited

American Heart Association (n.d.) Good vs. Bad Cholesterol. Retrieved from

Hendrickson, K (n.d.) Why Do Doctors Monitor the Concentration of LDL & HDL?, Retrieved from

Kamps, A (n.d.) How Do LDL and HDL Differ Structurally and Functionally?, SFGate. Retrieved from

MedHelp (n.d) Heart Disease. Retrieved from:

MedHelp (January, 2011) What other molecules in a patient's blood are monitored along with LDL and HDL? Retrieved from

National Cholesterol Education Program (n.d.) High Blood Cholesterol: What You Need To Know. Retrievedfrom

WebMD (n.d.) Cholesterol & Triglycerides Health Center. Retrieved from:

WebMD (n.d.) Understanding your cholesterol test results. Retrieved from