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.
What is an HDL test?
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.
Why is it necessary?
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, leading toTrusted Source conditions such as:
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.
Having low levels of HDL cholesterol can be of more concern, as it can indicate that the person is at riskTrusted Source of developing heart disease. Low levels can occur due to:
low levels of exercise
Who should have a cholesterol test?
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 9–11 yearsTrusted Source and young adults aged 17–21 years have this test.
Some people need the test more often. Risk factors that require more frequent cholesterol checks include: