A high-density lipoprotein (HDL) test measures the level of good cholesterol in your blood. Cholesterol is a waxy substance that’s found in all of the cells in your body. It has several different functions, including helping to build your body’s cells. Cholesterol is carried through the bloodstream attached to proteins called lipoproteins.
Two types of cholesterol in your body are HDL, which is the good cholesterol, and low-density lipoprotein (LDL), or bad cholesterol. HDL is known as the good cholesterol because it carries LDL, triglycerides, and harmful fats and returns them to your liver for processing. When HDL reaches your liver, the liver breaks down the LDL, turns it into bile, and removes it from your body.
The body is made up mostly of LDL cholesterol. LDL is considered bad cholesterol because high levels in the body can lead to plaque buildup in the arteries. This can result in heart disease or a stroke. Research has shown people with healthy HDL cholesterol levels are at a lower risk for coronary artery disease. Your doctor can check your cholesterol levels using a simple test.
An HDL test is also known as an HDL-C test. It’s one of several tests your doctor can use to check your cholesterol levels. This full set of tests is known as a complete cholesterol test, a lipid profile, or a lipid panel. Doctors routinely use this group of tests to determine the risk of developing heart disease.
The HDL test specifically looks at the level of HDL in your blood. An HDL test may also be ordered as a follow-up test if you have high results on your cholesterol-screening test.
The American Heart Association recommends that all adults age 20 or older have their cholesterol checked every four to six years. Your doctor may order an HDL test as part of a regular checkup.
Doctors may perform the test regularly for people who are at risk for heart disease, including those who:
- have diabetes
- have a family history of heart disease
- have high blood pressure
- are men over the age of 45
- are women over the age of 55
- use tobacco
- have heart disease or have had a heart attack
Your doctor may also order the test to monitor the effectiveness of treatments or to see if lifestyle changes such as diet, exercise, or smoking cessation are successful at lowering your cholesterol levels.
An HDL test requires a simple, routine blood draw. This rarely causes any serious issues. The risks of giving a blood sample include:
- bleeding under the skin, or a hematoma
- excessive bleeding
Your doctor will give you complete instructions on how to prepare for the test. These may include not taking certain medications for a short period or fasting for up to 12 hours before the test.
You shouldn’t have an HDL test when you’re sick. Cholesterol levels are temporarily lower during acute illness, immediately following a heart attack, and during stressful events like surgery or an accident. It’s recommended that you wait at least six weeks after any illness before you have your cholesterol measured. In women, HDL cholesterol can also change during pregnancy. You should wait at least six weeks after having a baby before your HDL is measured.
The HDL test is quick and relatively painless. A healthcare provider will draw a blood sample using a needle. You’ll feel the sting of the needle where the blood sample is taken. Some tests, such as home tests, only need a drop of blood taken using a small needle called a lancet.
When they draw enough blood into the airtight bottle attached to the needle, they’ll package the sample and send it to a laboratory for testing. If you feel woozy or lightheaded after the blood draw, you may rest and possibly have a snack or a sugary drink to help you feel better.
Optimal levels of HDL cholesterol are over 60 milligrams per deciliter (mg/dL). HDL levels that are below 40 mg/dL for men and 50 mg/dL for women indicate an increased risk of heart disease.
You can have high cholesterol and not have any symptoms. It’s important to get a cholesterol test regularly, especially if you have any of the risk factors for heart disease.