There are two major types of lipids that circulate through your blood: cholesterol and triglycerides. Because cholesterol and triglycerides are lipids, they are hydrophobic, which means that cannot dissolve in water -- or your blood. Maintaining the normal levels of cholesterol and triglycerides is important in preventing atherosclerosis, which is the buildup of plaque in the arteries, and reducing your risk of heart disease and stroke.
LDL Cholesterol
Low-density lipoprotein, or LDL, cholesterol is the type of cholesterol that people often refer to as bad cholesterol. This is because LDL cholesterol deposits cholesterol in your arteries. If you have too much LDL cholesterol, your risk of heart disease increases significantly. For healthy people, the recommended level for LDL cholesterol is less than 100 mg/dL, although levels that fall between 100 and 129 mg/dL are considered near ideal. If you have existing heart disease or have several other risk factors that put you at a high risk for heart disease, LDL cholesterol levels below 70 mg/dL are considered best.
HDL Cholesterol
High-density lipoprotein, or HDL, cholesterol is the type of cholesterol that is often called the good cholesterol. HDL cholesterol helps remove excess cholesterol from your arteries and brings it back to your liver for removal from the body. Because of its role in removing excess cholesterol, it is best to have high levels of HDL cholesterol. HDL cholesterol levels of 60 mg/dL and above are considered best.
Total Cholesterol
Total cholesterol represents the combined total of LDL cholesterol and HDL cholesterol. Normal total cholesterol levels are generally defined as less than 200 mg/dL. If your total cholesterol is between 200 and 239 mg/dL, it is described as borderline high, and total cholesterol measurements of 240 mg/dL and above are high. The American Academy of Family Physicians notes that if your total cholesterol is high because of your LDL cholesterol, you are at an increased risk of heart disease, but if it is high due to HDL cholesterol, your risk of heart disease is not increased.
Triglycerides
Because high triglycerides are a risk factor for heart disease, triglycerides are often measured with cholesterol levels as a part of a screening process called a lipid profile. Triglycerides below 150 mg/dL are considered normal. Triglyceride levels between 150 and 199 mg/dL are borderline high, and levels between 200 and 499 mg/dL are high. Triglyceride levels of 500 mg/dL are very high and put you at a significantly increased risk of heart disease.
