What is LDL/HDL Ratio?
Also Known As:
High-Density Lipoprotein Test, High-Density Lipoprotein Cholesterol Test, HDL-C Test, Good Cholesterol Test
An HDL cholesterol test measures the amount of cholesterol found inside high-density lipoproteins (HDL) in a sample of your blood.
Cholesterol is a waxy substance that helps the cells in your body function properly. However, the buildup of certain types of cholesterol in your arteries can heighten the risk of heart disease, stroke, heart attacks, and other health problems.
HDL cholesterol (HDL-C) is often known as “good cholesterol” because it is associated with better cardiovascular health. In contrast, low-density lipoprotein (LDL) cholesterol is called “bad cholesterol” because it is associated with cardiovascular disease.
HDL cholesterol is almost always measured along with total cholesterol, and these two measurements are core parts of the lipid panel test. A lipid panel is a common test measuring HDL cholesterol, total cholesterol, LDL cholesterol, and fat molecules called triglycerides.
The purpose of HDL cholesterol testing is to assess your cardiovascular health, including your risk for heart disease. HDL cholesterol is considered to be a good type of cholesterol that is associated with a lower risk of coronary heart disease events.
Measuring HDL cholesterol and total cholesterol together in the same blood sample allows the doctor to easily calculate the ratio of HDL cholesterol to non-HDL cholesterol. This is important for assessing your cardiovascular health and allows the doctor to understand the relative amounts of good and bad cholesterols.
Testing of HDL cholesterol can play a role in screening, monitoring, and diagnosing problems that affect your heart, blood vessels, and blood circulation.
Screening is looking for health problems before any symptoms have occurred. The goal of cardiovascular screening is to better address problems by finding them at an earlier stage.
Screening is one of the most common ways that HDL cholesterol testing is used. In both children and adults who do not have symptoms of cardiovascular problems, cholesterol levels may be checked periodically.
A low level of HDL cholesterol has been tied to an elevated risk of problems like heart disease and stroke. It is also associated with type 2 diabetes. For this reason, HDL-C testing can be used for the early detection of potentially serious health concerns.
Based on an analysis of blood levels of total cholesterol, HDL cholesterol, and LDL cholesterol, doctors can use special formulas to determine whether a patient’s risk level is borderline, intermediate, or high.
In many cases, it is necessary to track cholesterol levels over time. This is known as monitoring, and it is common for HDL cholesterol to be tested at set intervals. The most common situations in which HDL cholesterol is monitored over time include:
- After a prior abnormal cholesterol test: If you have had a previous cholesterol test with low HDL cholesterol or high LDL cholesterol, you may have ongoing testing to monitor your lipid levels.
- After a prior cardiovascular problem: If you have been diagnosed with heart disease or have had a heart attack in the past, cholesterol testing can be part of monitoring your health over time.
- After starting treatment to reduce cardiovascular risk: Sometimes doctors will recommend lifestyle changes or medications to improve your cholesterol levels, and ongoing testing can assess your response to the prescribed treatment.
Less often, cholesterol tests are for diagnosis, which is identifying the cause of a health problem after symptoms have started.
Doctors may order cholesterol tests if you have certain cardiovascular symptoms. HDL cholesterol levels are a consideration in the diagnosis of metabolic syndrome. Metabolic syndrome is a set of risk factors for diabetes, stroke, and coronary heart disease. Cholesterol testing can also be involved in identifying some health problems affecting other organs.
What does the test measure?
An HDL cholesterol test analyzes a sample of blood to see how much cholesterol is present within high-density lipoprotein (HDL) particles. Cholesterol is a waxy substance that is important for basic cell function. Cholesterol is transported through the body in the blood within lipoproteins, which are made up of fat and protein.
There are multiple kinds of lipoproteins that can carry cholesterol including high-density lipoproteins, low-density lipoproteins (LDL), and very-low-density lipoproteins (VLDL).
Cholesterol in LDL and VLDL particles can build up in the arteries and cause cardiovascular problems. In contrast, HDL particles transport cholesterol to the liver so that it can be eliminated from the body. Through this and other functions, HDL cholesterol helps protect against hardening and blockages of the arteries.
In practice, virtually all HDL cholesterol tests also measure total cholesterol, which is the sum of cholesterol found in all the different kinds of lipoproteins. By subtracting HDL cholesterol from total cholesterol, the doctor can determine the amount of non-HDL cholesterol that is present. In addition, tests like a lipid panel use a mathematical formula to calculate the amount of LDL cholesterol in your blood sample.
When should I get an HDL cholesterol test?
Whether an HDL cholesterol test is appropriate depends on your specific circumstances.
As a screening test, there are no universally agreed-upon recommendations regarding how often to measure cholesterol levels. In general, screening is started earlier for people with risk factors such as high blood pressure, cigarette smoking, diabetes, or a family history of heart disease at an earlier age. Ongoing cholesterol testing may occur more often in people with one or more of these risk factors.
People without an elevated risk for cardiovascular problems usually start screening at a later age and often have longer intervals between cholesterol tests.
Screening is frequently done with a lipid panel, especially for an initial test. However, some screening may be done with only a total cholesterol and HDL-C measurement.
When used to monitor cholesterol over time, HDL cholesterol testing may be recommended if you have already been diagnosed with coronary heart disease. Tracking cholesterol levels can also be important if you have had cardiovascular problems or abnormal cholesterol levels in the past. If you are receiving treatment for these issues, repeated HDL cholesterol testing may be used to monitor your response to therapy.
Although principally used to detect cardiovascular issues, abnormalities in HDL cholesterol can occur with other health problems affecting the thyroid, pancreas, or liver. As a result, cholesterol testing may be involved in the diagnostic process for a range of medical conditions.
How to get tested
There are several different ways that HDL cholesterol levels can be tested.
Your doctor may prescribe a laboratory test, which requires taking a blood sample from a vein in your arm in a medical office or hospital.
Some clinics, doctor’s offices, pharmacies, and events like health fairs also offer on-site cholesterol testing. Known as point-of-care testing, this test analyzes a drop of blood that comes from pricking your fingertip with a very small needle.
Can I take the test at home?
At-home tests are available that measure HDL cholesterol. There are various options for at-home HDL cholesterol testing.
An at-home self-test involves a fingerstick blood sample that provides results without having to send your sample to a lab. In these self-tests, a drop of blood is applied to a special test paper. The test paper either changes color based on your cholesterol levels or is inserted into a small device that analyzes your blood.
A self-collection test involves taking a fingerstick blood sample at home and then mailing it to a laboratory that measures the level of HDL cholesterol.
Some at-home tests only measure total cholesterol and do not provide a result for HDL cholesterol. For this reason, it is important to look closely at the test to determine if it includes a measurement of HDL-C.