Good vs. Bad Cholesterol

LDL (low-density lipoprotein) cholesterol is "bad" cholesterol, which carries mostly fat and only a small amount of protein from the liver to other parts of the body. A high LDL cholesterol level is considered a risk factor for coronary artery disease (CAD) because, under certain conditions, it can cause hardening of the arteries (atherosclerosis).

Cholesterol is measured either in milligrams per deciliter of blood (mg/dL) or in millimoles per liter of blood (mmol/L).

• An LDL cholesterol level of less than 100 mg/dL (less than 2.6 mmol/L) is considered optimal.
• 100 to 129 (2.6 to 3.35) is considered near optimal.
• 130 to 159 (3.35 to 4.10) is considered borderline high.
• 160 to 189 (4.12 to 4.88) is considered high.
• 190 and above (4.90 to 4.88) is considered very high.

People who have at least a moderate risk for developing heart disease (especially those who have diabetes) may benefit from lowering their LDL cholesterol levels. The specific target LDL level depends on a person's number and type of risk factors.

HDL (high-density lipoprotein) is sometimes called "good" cholesterol because it helps prevent cholesterol from building up in the arteries. HDL, which is made mostly of protein and only a small amount of fat, helps clear LDL (low-density lipoprotein), or “bad,” cholesterol from the body.

High levels of HDL appear to help protect against heart disease. A person who is at risk for heart disease may be advised to raise his or her HDL levels by eating a balanced diet, exercising and losing weight, and stopping tobacco use. In addition, medicines may be used to raise HDL levels.

Triglycerides are a type of fat that is found in the blood. They are the most common type of fat and are a major source of energy.

When a person eats, his or her body uses the calories it needs for quick energy. It converts excess calories into triglycerides and stores them in fat cells to use later. In normal amounts, triglycerides are very important to good health. But having high triglyceride levels may increase a person's risk of developing coronary artery disease (CAD). Very high triglycerides may lead to pancreatitis in certain people.

Triglyceride levels are categorized as follows:

• Below 150 milligrams per deciliter (mg/dL) is considered normal.
• 150 to 199 is borderline-high.
• 200 to 499 is high.
• 500 or higher is very high.