Some people refer to high-density lipoprotein (HDL) cholesterol as “good” cholesterol. A doctor can measure its levels with a blood test. Having unhealthy levels of HDL cholesterol can increase the risk of certain conditions, such as heart disease.
Lipoproteins are particles that carry cholesterol through the bloodstream. There are two main types: high- and low-density lipoproteins. These lend their names to two types of cholesterol: HDL cholesterol and LDL cholesterol. They are sometimes called “good” and “bad” cholesterol, respectively.
Cholesterol is a substance that the body uses to make cells, certain hormones, and vitamins. The liver makes all the cholesterol that the body needs, but a person can also consume it in foods.
Below, learn why a doctor may test HDL cholesterol levels and what the results can mean.
An HDL test is a blood test to measure HDL cholesterol levels. This might be part of a “lipid panel,” a test that can provide an overview of a person’s cholesterol levels.
Lipid panels measure amounts of the following substances in a blood sample:
- HDL cholesterol
- total cholesterol
- triglycerides, the most common type of fat in a person’s blood
Doctors calculate the amount of LDL cholesterol in a person’s blood using information from a lipid panel. However, certain health conditions can affect the accuracy of this calculation. This means that a person may need more than one test to determine their LDL cholesterol levels.
Doctors may measure HDL levels when trying to work out a person’s total cholesterol levels.
The HDL test may also be helpful in monitoring how a person is responding to cholesterol-controlling treatment.
Having high levels of LDL cholesterol can result in a buildup of plaque within blood vessels. Plaque is a substance made of calcium, fat, cholesterol, and cell waste. A buildup within arteries can cause them to narrow or become blocked,
Determining a person’s overall cholesterol levels can help indicate their risk of heart disease. And measuring HDL cholesterol levels, in particular, can give doctors useful information.
Having high levels of HDL cholesterol is generally a good thing. HDL cholesterol carries LDL cholesterol back to the liver, where the body breaks it down and removes it from the body.
However, some conditions can cause HDL cholesterol levels to become too high.
An article in the journal Science focuses on a rare genetic variation that can lead to abnormally high HDL cholesterol levels. The variation changes how this cholesterol works in the body and can lead to an increased risk of heart disease.
Anyone who is over 20 years old and has no risk factors for heart disease should have their cholesterol levels tested every 4–6 years, according to the American Heart Association (AHA).
The Centers for Disease Control and Prevention (CDC) also recommends that children aged
Some people need the test more often. Risk factors that require more frequent cholesterol checks include:
If a person is having an HDL blood test as part of a lipid panel, their doctor may ask them to fast for 9–12 hours beforehand. When a person fasts, they do not eat or drink anything but water.
A study from 2018 found that fasting before a lipid panel can be useful for people with certain risk factors.
Some doctors believe that fasting before a lipid panel produces more accurate results. However, research from 2017 suggests that the difference made by fasting is insignificant.
It is important to follow instructions carefully and let the healthcare professional know about current illness or pregnancy before the test. These factors can affect HDL cholesterol levels.
To measure HDL cholesterol levels, a healthcare professional takes a blood sample from a vein in the arm or a finger prick.
They then send this sample to a laboratory, which carries out the analysis.
A doctor will describe the test results and any treatment going forward.
The test results show cholesterol levels in milligrams per deciliter of blood (mg/dl). The National Library of Medicine gives the following ranges for HDL cholesterol levels in adults:
|Major risk for heart disease||Borderline||Optimal|
|Less than 40 mg/dl||40–59 mg/dl||60 mg/dl or higher|
If a person’s HDL cholesterol level is too low, a doctor may recommend treatment to increase it. The options may include:
- having a more healthy diet
- maintaining a moderate weight
- getting more exercise
- quitting smoking
- reducing alcohol intake
- treating diabetes, if it is present
Also, because certain drugs reduce HDL cholesterol levels, the doctor may recommend a change to a person’s medication regimen.
HDL cholesterol is known as “good” cholesterol, and high levels can be beneficial. However, levels that are too high or low can increase the risk of heart disease.
Doctors often recommend having cholesterol levels checked every 4–6 years, but some people, such as those with a high risk of heart disease, should have these tests more frequently.
The test involves giving a blood sample. This might be part of a lipid panel, a test that helps doctors calculate overall cholesterol levels.
Before an HDL blood test, a person may need to fast for 9–12 hours. Once the results come in, the doctor will describe what they mean and whether any treatment is necessary.
If a person has any concerns about their cholesterol, they should speak with a healthcare professional.