Cholesterol is "a waxy, fat-like substance that occurs naturally in all parts of the body," according to MedlinePlus. Total cholesterol is a measure of two types of blood cholesterol as well as triglycerides, another type of fat, in your blood.

Types

Low-density lipoprotein (LDL) and high-density lipoprotein (HDL) are the two major types of cholesterol. LDL is considered "bad" because it is more likely to clog blood vessels and increase the risk of heart disease. HDL, or the "good" type, helps clear LDL from the blood and decrease the danger of heart disease.

Testing

The total cholesterol blood test evaluates risk for coronary artery disease. It is typically done as part of a lipid profile, which measures specific levels of LDL, HDL and triglycerides, notes MedlinePlus.

Measurements

Cholesterol levels are measured in milligrams per deciliter (mg/dL) of blood. A total cholesterol result of less than 200 mg/dL is desirable, 200 to 239 mg/dL is borderline high risk, and 240 mg/dL and greater is high risk. Individual HDL and LDL levels are also important, with an HDL level of more than 60 mg/dL being optimal. An HDL of less than 40 mg/dL for men and 50 mg/dL for women indicates risk. An LDL measurement of less than 100 mg/dL is optimal, whereas a reading of 190 mg/dL or more is dangerously high.

Considerations

Physicians take into account risk factors that include "age, family history, smoking and high blood pressure," in addition to cholesterol tests, notes the American Heart Association.

Prevention

Your body needs cholesterol, but too much will create plaque in the arteries and cause serious heart disease, including heart attack and stroke. Exercise, diet and medication can help control total cholesterol.

Source:

MedlinePlus: Cholesterol

MedlinePlus: Cholesterol Test

American Heart Association: What Your Cholesterol Levels Mean