What is HDL?

HDL stands for high-density lipoprotein, a type of cholesterol found in our blood. It is essential for our heart health and is often referred to as “good cholesterol.” But why is it considered “good,” and why is it so important for our health? Read on to get all the valuable information.

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Table of Contents

• What does HDL mean?
• Why is HDL cholesterol important?
• What is a healthy HDL level?
• What are the causes of high or low HDL levels?
• What are the consequences of high or low HDL?
• How can I test my HDL level?
• What should you do if your HDL cholesterol is too low?
• Summary

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What does HDL mean?

High-density lipoprotein (HDL) is a type of cholesterol often referred to as “good cholesterol.” It plays an essential role in maintaining cardiovascular health by helping to remove excess cholesterol from the bloodstream.

HDL is made up of lipids (fats) and proteins and is produced primarily in the liver and intestines. These particles circulate in the blood and transport excess cholesterol away from arteries, carrying it back to the liver, where it is broken down and removed from the body.

Unlike low-density lipoprotein (LDL) (often called “bad cholesterol”) HDL reduces the risk of atherosclerosis (plaque buildup in arteries), stroke, and heart disease.

Source: Hartstichting.

Why is HDL cholesterol important?

HDL cholesterol acts like a cleanup system for your bloodstream. It helps to:

• Remove excess cholesterol from artery walls
• Transport cholesterol to the liver for disposal
• Reduce the risk of blocked arteries and cardiovascular events
• Offset some of the negative effects of LDL (“bad”) cholesterol

While having high HDL levels is generally considered a good thing, very high levels (especially above 2.5 mmol/L or 97 mg/dL) may also be associated with certain health risks, particularly in people with other underlying conditions such as chronic inflammation or hypertension. Always consult with a healthcare provider when interpreting your results.

What is a healthy HDL level?

Here are the normal and abnormal HDL cholesterol ranges for adults, which vary by sex:

Group	Low HDL	Normal HDL	High HDL
Adult Males	Below 40 mg/dL	40 to 80 mg/dL	Above 80 mg/dL
Adult Females	Below 50 mg/dL	50 to 80 mg/dL	Above 80 mg/dL
Children/Teens	—	45 to 80 mg/dL	Above 80 mg/dL

Source: Cleveland Clinic, 2025

What are the causes of high or low HDL levels?

A low HDL level can have various causes:

• Tangier disease: A genetic disorder that leads to particularly low HDL cholesterol levels.
• Familial combined hyperlipidemia: A genetic condition in which HDL cholesterol is too low and LDL cholesterol is too high.
• Metabolic syndrome: A cluster of risk factors for cardiovascular diseases often associated with lower HDL levels.
• Overweight/obesity: Excess weight can lead to a lower HDL level.
• Smoking or tobacco use: Tobacco contains nicotine, which lowers HDL levels. This applies to all tobacco products, including e-cigarettes.

An elevated HDL level is defined as a value above 80 mg/dL. There are several reasons why the HDL level may be abnormally high:

• Genetic mutations: Certain genetic changes can cause the body to produce too much HDL cholesterol or have difficulty eliminating it. A mutation in the CETP gene, for example, can lead to an HDL level of over 150 mg/dL.
• Hyperthyroidism: An overactive thyroid.
• Primary biliary cholangitis: A liver disease that impairs bile flow.
• Alcohol abuse
• Certain medications

Source: Cleveland Clinic, 2022

It is important to talk to your doctor about the causes of your HDL level and determine whether treatment is necessary.

What are the consequences of high or low HDL?

A high HDL level is generally considered beneficial for health and can protect against cardiovascular disease. Only in extremely high values might there be exceptions. A low HDL level is more concerning, especially if it is not in balance with the LDL level. Typically, there is a balance between “good” and “bad” cholesterol, with the ratio being two parts LDL to one part HDL.

How can I test my HDL level?

With the Homed-IQ Cholesterol and Lipids Test, you can measure your HDL level from home. You will also measure your LDL and total cholesterol levels. The test is conducted through a simple finger prick. A certified laboratory then analyzes your blood sample, and you can view the result within a few days.

How often should you test HDL?

There is no fixed recommendation for the frequency of HDL tests.

• Every 4-6 years for healthy adults
• Annually if you have cardiovascular risk factors (e.g. high blood pressure, diabetes, family history)
• After major lifestyle changes, such as weight loss, quitting smoking, or dietary overhauls

You can check your HDL level at any time using a home test. For most adults, cholesterol levels remain relatively stable over time. Nonetheless, changes in lifestyle or diet may warrant a recheck of your HDL levels.

What should you do if your HDL cholesterol is too low?

Improving your HDL levels naturally can help protect your cardiovascular system. Consider the following strategies:

• Exercise regularly: Aim for at least 150 minutes of moderate aerobic activity per week
• Quit smoking: This can quickly increase HDL levels
• Eat healthy fats: Focus on monounsaturated fats (olive oil, avocados) and omega-3s (fatty fish, flaxseed)
• Maintain a healthy weight: Even small weight loss can improve HDL
• Limit refined sugars and trans fats
• Drink alcohol only in moderation (if at all)

There are no medications that directly target HDL levels, so lifestyle changes remain the most effective way to improve them.

Sources: Ernährungszentrum; Mayo Clinic, 2022

Summary

HDL cholesterol is essential for maintaining a healthy cardiovascular system. It helps remove excess cholesterol from the bloodstream and can reduce your risk of heart disease. While higher levels are generally beneficial, balance is key. Low HDL levels can increase your risk of health complications—but with the right lifestyle changes and regular monitoring, you can take control of your heart health.

References

Nederlands Huisartsen Genootschap (NHG). (2019, March 9). Laboratoriumdiagnostiek cardiovasculair risicomanagement – volledige tekst. Retrieved August 21, 2023, from https://www.nhg.org/themas/publicaties/laboratoriumdiagnostiek-cardiovasculair-risicomanagement-volledige-tekst

Hartstichting. (2019, March 9). Risico’s en gevolgen van een hoog cholesterol. Retrieved August 21, 2023, from https://www.hartstichting.nl/risicofactoren/gids-cholesterol/risico-s-en-gevolgen?tab=2

Voedingscentrum. (n.d.). Bioactieve stoffen. Retrieved August 21, 2023, from https://www.voedingscentrum.nl/encyclopedie/bioactieve-stoffen1.aspx

Mayo Clinic. (n.d.). HDL cholesterol: How to boost your ‘good’ cholesterol. Retrieved August 21, 2023, from https://www.mayoclinic.org/diseases-conditions/high-blood-cholesterol/in-depth/hdl-cholesterol/art-20046388

Cleveland Clinic. (2022, October 28). What to know about HDL cholesterol. Retrieved August 21, 2023, from https://my.clevelandclinic.org/health/articles/24395-hdl-cholesterol

Cleveland Clinic. (2022, October 28). What to know about HDL cholesterol. Retrieved August 21, 2023, from https://my.clevelandclinic.org/health/articles/24395-hdl-cholesterol

Cleveland Clinic (2025). https://my.clevelandclinic.org/health/articles/24395-hdl-cholesterol