HDL, or high-density lipoprotein, is a cholesterol-containing molecule that affects the health of your cardiovascular system by removing harmful LDL, or low-density lipoprotein, cholesterol from your bloodstream. Having normal levels of HDL in your blood can prevent increases in your heart disease risks, while greater levels of HDL can actively lower these risks.
Normal HDL Levels
Normal HDL levels for men fall between 40 and 50 milligrams per deciliter of blood, while normal levels for women fall between 50 and 60 mg/dL, according to the American Heart Association. If you are male, an HDL level below 40 mg/dL typically increases your heart disease risks, while levels below 50 mg/dL pose a similar increase in risks if you are female. The difference between HDL levels between men and women largely results from the varying effects of male and female sex hormones.
HDL Factors
The American Heart Association lists a number of factors that can decrease your HDL below normal levels. These include physical inactivity, smoking and carrying excess weight for your height and gender. Conversely, you can increase your HDL levels toward normal by exercising regularly, quitting or avoiding smoking and lowering your weight to healthy levels.
Triglycerides
You may also have lower than normal HDL levels if your blood contains high levels of triglycerides, a type of fat often linked to the presence of high LDL levels, the American Heart Association reports. The association defines high triglycerides as a level ranging between 200 and 499 mg/dL and very high triglycerides as a level at or above 500 mg/dL. Factors that may increase your triglyceride levels include consumption of a diet containing extremely high amounts of carbohydrates, excessive alcohol intake, smoking, obesity and physical inactivity.
HDL Protection
HDL cholesterol achieves its effects by transporting LDL cholesterol to your liver, where it is eliminated from your system, according to the National Heart Lung and Blood Institute. Generally speaking, the higher the level of HDL you have in circulation, the lower your chances are of developing heart disease. HDL levels greater than 60 mg/dL may actively protect you from heart-related illness, the American Heart Association reports.
Considerations
Doctors typically evaluate your HDL levels in relation to your levels of LDL and triglycerides, as well as in relation to your overall, or total, cholesterol levels, according to the American Heart Association. The testing done to record these different values is called a lipoprotein profile. The National Heart Lung and Blood Institute recommends that you get a complete lipoprotein profile to fully assess your cholesterol risks. If you cannot get a complete profile, the institute recommends a check of your total cholesterol and HDL as a minimum acceptable alternative.
