HDL cholesterol is the well-behaved "good cholesterol." This friendly scavenger cruises the bloodstream. As it does, it removes harmful bad cholesterol from where it doesn't belong. High HDL levels reduce the risk for heart disease -- but low levels increase the risk.
What Makes HDL Cholesterol so Good?
HDL is short for high-density lipoprotein. Each bit of HDL cholesterol is a microscopic blob that consists of a rim of lipoprotein surrounding a cholesterol center. The HDL cholesterol particle is dense compared to other types of cholesterol particles, so it's called high-density.
Cholesterol isn't all bad. In fact, cholesterol is an essential fat. It provides stability in every cell of your body.
To travel through the bloodstream, cholesterol has to be transported by helper molecules called lipoproteins. Each lipoprotein has its own preferences for cholesterol, and each acts differently with the cholesterol it carries.
Experts believe HDL cholesterol may act in a variety of helpful ways that tend to reduce the risk for heart disease:
- HDL cholesterol scavenges and removes LDL -- or "bad" -- cholesterol.
- HDL reduces, reuses, and recycles LDL cholesterol by transporting it to the liver where it can be reprocessed.
- HDL cholesterol acts as a maintenance crew for the inner walls (endothelium) of blood vessels. Damage to the inner walls is the first step in the process of atherosclerosis, which causes heart attacks and strokes. HDL scrubs the wall clean and keeps it healthy
What Are Good Levels for the HDL Cholesterol?
- HDL cholesterol levels greater than 60 milligrams per deciliter (mg/dL) are high. That's good.
- HDL cholesterol levels less than 40 mg/dL are low. That's not so good.
In general, people with high HDL are at lower risk for heart disease. People with low HDL are at higher risk.
What Can I Do if my HDL Cholesterol Level Is Low?
If your HDL is low, you can take several steps to boost your HDL level and reduce your heart disease risk:
- Exercise. Aerobic exercise for 30 to 60 minutes on most days of the week can help pump up HDL.
- Quit smoking. Tobacco smoke lowers HDL, and quitting can increase HDL levels.
- Keep a healthy weight. Besides improving HDL levels, avoiding obesity reduces risk for heart disease and multiple other health conditions.
In certain cases, your doctor may recommend medication to improve your cholesterol level. Remember that multiple factors besides cholesterol contribute to heart disease. Diabetes, smoking, high blood pressure, obesity, and genetics are all important as well.
Because so many factors contribute to heart disease, cholesterol isn't everything. People with normal HDL cholesterol can have heart disease. And people with low HDL levels can have healthy hearts. Overall, though, people who have low HDL cholesterol will have greater risk of developing heart disease than people with high HDL levels.
Experts recommend follow-up cholesterol testing every five years for most people. People with abnormal lipid panels, or who have other risk factors, may need more frequent cholesterol tests.
If you have high cholesterol or low HDL levels, take steps to increase HDL cholesterol such as eating right, exercising regularly, and not smoking. Lifestyle changes can make a big difference for most people and may prevent heart disease and stroke.