HDL, or high-density lipoprotein, is commonly referred to as the "good cholesterol." Unlike LDL, the low-density lipoproteins that should be at low levels, HDL levels in the body are supposed to be fairly high. HDL helps excess cholesterol return to the liver for excretion through the gastrointestinal system. HDL is known as good cholesterol because it aids in the removal of cholesterol that can block arteries and reduce blood flow.
Good cholesterol levels are obtained with a simple blood test. The blood test is ordered by a physician either as part of a routine physical or for screening purposes. This blood test is called a lipid profile, and it measures both HDL and LDL levels along with total cholesterol. The test provides a doctor with indicators that help evaluate a patient's risk factor for heart disease. Cholesterol levels are measured in milligrams per deciliter of blood.
When a lipid profile is ordered, the doctor may require a 12-hour fasting test and may also require certain medications to be temporarily stopped. Cholesterol testing is important, especially in patients who are already at risk for heart disease, such as smokers, diabetics, or people with high blood pressure or weight problems. Each person's target cholesterol level varies slightly, but generally, the good cholesterol levels should be 60 mg/dL or higher and not less than 40 mg/dL to avoid being at risk.
Unlike LDL levels, which are sometimes targeted by a cholesterol lowering diet, HDL levels are linked more to a person's lifestyle than diet alone. Smoking, obesity, and sedentary activities are directly linked to low blood HDL levels. Weight loss, smoking cessation and exercise will raise HDL levels. However, controlling total cholesterol is a combination of raising the good and lowering the bad — a process that should include both dietary and lifestyle changes. When lifestyle modification and diet alone are not enough, or if a patient refuses to make changes, a doctor may prescribe a medication for raising HDL levels.