HDL: The Good Cholesterol

Medically Reviewed by Poonam Sachdev on January 08, 2024
7 min read

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.

HDL cholesterol is the well-behaved "good cholesterol." This friendly scavenger cruises your bloodstream. As it does, it removes harmful bad cholesterol from where it doesn't belong. High HDL levels reduce your risk for heart disease--but low levels increase the risk.

Cholesterol isn't all bad. In fact, cholesterol is an essential fat. It provides stability in every cell of your body.

To travel through your 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 your risk for heart disease:

  • HDL cholesterol scavenges and removes low-density lipoprotein (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.

High-density lipoprotein, or HDL, carries cholesterol to your liver. There it gets removed before it has a chance to build up in your arteries.

Low-density lipoprotein, or LDL, transports cholesterol directly to your arteries. This can result in a plaque buildup--called atherosclerosis--that can lead to heart attack and stroke.

A cholesterol test or lipid panel shows your level of HDL cholesterol. What do the numbers mean?

In general, people with high HDL are at lower risk for heart disease. People with low HDL are at higher risk.

A lipid panel typically measures five different types of lipids, or fat molecules, in your blood. Measurements are given in milligrams per deciliter (mg/dL):

  • Total cholesterol: Your overall cholesterol level, which is a combination of low-density lipoprotein (LDL), high-density lipoprotein (HDL), and very low-density lipoprotein (VLDL)

  • Low-density lipoprotein (LDL): A type of cholesterol that can collect in your blood vessels, increasing the risk of heart disease; also known as "bad cholesterol"

  • High-density lipoprotein (HDL): A type of cholesterol that helps to decrease buildup of LDL in the blood vessels; also known as "good cholesterol" 

  • Very low-density lipoprotein (VLDL): Like LDL, it's also a "bad" form of cholesterol. If you fasted before your lipid panel test, higher-than-normal amounts of VLDL cholesterol are associated with abnormal lipid metabolism. 

  • Triglycerides: A type of fat that comes from the foods we eat. Higher amounts of triglycerides are associated with heart disease and inflammation of the pancreas.

Optimal HDL Levels

The higher your HDL number, the better. The optimal level of HDL to protect you from heart disease is 60 mg/dL or above. However, high levels don't protect you from the negative impact of high LDL.

Normal HDL Levels

Recommended HDL cholesterol levels vary based on sex: 

  • For men and those assigned male at birth (AMAB), HDL levels should be 40 mg/dL or higher to lower the risk of heart disease. 
  • For women and those assigned female at birth (AFAB), HDL should be 50 mg/dL or higher to lower the risk. 
  • For children ages 2-19, an HDL level of 45 mg/dL or above is considered to be normal.

Low HDL Levels

Your HDL cholesterol is considered low in these ranges:

  • Men/AMAB: Less than 40 mg/dL 
  • Women/AFAB: Less than 50 mg/dL  

In general, low levels of HDL can contribute to having a higher level of LDL. That's because HDL cholesterol helps your body get rid of LDL -- the "bad" cholesterol. It moves LDL away from arteries and toward the liver, which eliminates the LDL from your body. If you don't have enough HDL helping to reduce your LDL level, it doesn't lower your risk of heart disease, heart attack, and stroke.

There are several causes of low HDL, including: 

  • Tangier disease: This genetic condition (inherited from parents) causes low levels of HDL cholesterol. 

  • Familial combined hyperlipidemia: People with this inherited condition (passed on from one or both parents) have trouble processing cholesterol. That means HDL cholesterol can be too low and LDL can be too high.

  • Metabolic syndrome: If you have metabolic syndrome, low HDL may be part of it. Multiple health conditions combine in this syndrome and increase risk of heart disease, Type 2 diabetes, and stroke.

  • Overweight/obesity: If you have extra weight, or a body mass index (BMI) higher than 25, your HDL cholesterol is likely to be lower. In addition, lower levels of HDL cholesterol are associated with obesity, especially fat around the abdomen.  

  • Smoking or tobacco use: The nicotine in tobacco lowers your HDL. All tobacco products include nicotine, including e-cigarettes.

  • Medication: Certain medicines may lower HDL levels, such as beta blockers, some diuretics, and others.

High HDL Levels

For adults, anything above 80 mg/dL is considered high. An abnormally high level of HDL can cause problems, too. In some cases, it may speed up atherosclerosis--the buildup of fats on the artery walls. 

High HDL cholesterol could be caused by: 

  • Genetic mutations: Some changes in your genetic makeup can cause your body to produce too much HDL or have trouble removing it. 

  • Primary biliary cholangitis: This disease makes it hard for bile (a fluid your liver makes) to pass through your digestive system. Your body can't break down fats, which can cause high blood cholesterol. 

  • Alcohol use disorder: Alcohol consumption is known to raise "good" cholesterol levels. But more isn't necessarily better. Some studies indicate that the increases in HDL from alcohol don't provide any benefit. Drinking also increases your risk of heart disease, stroke, and liver disease.  

  • Medications: Some medicines that help lower LDL cholesterol, such as statins, may also raise HDL cholesterol levels to abnormally high levels.  

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.
  • Eat a Mediterranean diet. It has repeatedly been shown to raise HDL levels. The Mediterranean diet consists of healthy fats (mainly olive oil), vegetables, fruits, and whole grains. 
  • Limit alcoholic beverages. If you're drinking alcohol, keep your intake to:
    • One drink per day for all women, or for men older than 65 
    • Up to two drinks a day for men 65 and younger

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 a 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.

The "good" cholesterol, HDL, is important because it's involved in clearing "bad" cholesterol (LDL) from your body. Low levels of HDL can increase your risk of heart disease, heart attack, and stroke. Certain health conditions can lower HDL levels. Lifestyle changes and specific treatment plans can boost your HDL cholesterol to support your overall health.

What is a good level of HDL?

For men and those assigned male at birth (AMAB), HDL levels should be 40 mg/dL or higher to lower the risk of heart disease. For women and those assigned female at birth (AFAB), HDL should be 50 mg/dL or higher to lower the risk. The optimal level of HDL to protect you from heart disease is 60 mg/dL or above. 

Is HDL cholesterol good or bad cholesterol? 

High-density lipoprotein, or HDL, is considered to be "good" because it carries cholesterol to your liver, where it gets removed before it has a chance to build up in your arteries.  

What is a healthy HDL level by age? 

  • People 19 and younger: More than 45 mg/dL

  • Men/AMAB  20 and older: More than 40 ml/dL

  • Women/AFAB 20 and older: More than 50 mg/dL

How do I raise my HDL?

Lifestyle changes can make a difference. Here are some ways to help raise your HDL cholesterol:

  • Exercise for 30-60 minutes most days

  • Quit smoking

  • Avoid obesity by maintaining a healthy weight

  • Eat a Mediterranean diet

  • Drink alcohol in moderation

Work with your doctor to address any medical conditions and make any necessary changes in medication to help improve your HDL level.