What are your concerns?

Hard to understand


Or copy link


LDL Test (Low-Density Lipoprotein): Why and How is it Done?

LDL Test (Low-Density Lipoprotein): Why and How is it Done?

Low Density Lipoprotein (LDL) cholesterol is known to be the “bad” cholesterol because it can lead to fatty artery buildups (atherosclerosis). The condition narrows the arteries and raises the risk of heart stroke, peripheral artery disease, heart attack, or PAD.

Not all cholesterol is bad. It is an essential fat required by the cells in your body. Most cholesterol comes from the food you eat, and some is made by your liver. It cannot dissolve in the blood, so it’s taken by proteins and carried towards where it needs to go. These carriers are known as lipoproteins.

LDL is a microscopic glob consisting of an outer lipoprotein rim and a core for cholesterol. The full name is “low-density lipoprotein.” It’s bad because it becomes part of the plaque, the material that can clog the arteries, making heart attacks and strokes more likely.

A low density lipoprotein or LDL test measures the level of such low-density lipoprotein in your body.

Why is an LDL test done?

The bad cholesterol test or LDL test is performed to assess the risk of developing heart disease and to track the lipid-lowering therapy efficacy. The LDL test will help to determine the risk of heart disease for an individual and help guide decisions about what care could be best if the person is at high risk or borderline. This test is also done to monitor the effectiveness of treatment in people who are being treated for high LDL values or those diagnosed with heart problems.

The findings are considered in accordance with other established cardiovascular risk factors in order to develop and implement a treatment plan.

Treatment options can include changes in lifestyle such as diet and exercise, or lipid-lowering medicines such as statins.


Laboratory LDL test generally might require fasting of 9 to 12 hours; only water is allowed. Your health care provider may sometimes decide to test you without having to fast.

Follow any instructions given to you by your doctor, and inform the blood drawing technician whether you have fasted or not. Testing without fasting can be performed for adolescents with no risk factors.

Let your doctor know about any medications that you may be taking. Follow your doctor’s advice on continuation or stopping of medicines temporarily before the test.

LDL test

Understanding the Results

Low density lipoprotein reflects bad cholesterol. Consider the “L” as “lousy” in LDL. High levels of LDL increase the likelihood of a heart disease.

Your real LDL target depends on whether you have heart disease risk factors, such as diabetes or high blood pressure, or not. However, generally the LDL results are as below:

  • Less than 100 mg/dL: Optimal
  • 100-129 mg/dL: Near optimal
  • 130-159 mg/dL: Borderline high
  • 160-189 mg/dL: High

Your doctor will discuss strategies with you to lower your LDL by some percentage based on your risk for heart disease.

Such approaches usually include improvements in lifestyle — including dietary changes and exercise— including use of medicine to lower cholesterol. You and your physician need to agree together on the best approaches for your particular situation.

Why Should This Test be Repeated?

Normally, screening tests for lipid profiles for adults 20 years or older are recommended. Because of the modern lifestyle, studies have shown many patients who are under 15 but still have a significant risk for heart disease. However, it is best to follow medical advice.

This bad cholesterol test may be repeated at regular intervals for people at risk of the following atherosclerosis risk factors, as a part of your yearly health check-up or if the doctor recommends.

  • Diabetes
  • If they are smokers
  • High blood pressure
  • Premature heart disease or very high cholesterol level in the immediate family
  • Obesity

This test can be repeated every one or two years if the blood test result is normal and the risk is low. For those under treatment for high cholesterol or any other heart disease, your doctor may advise you to repeat the test every few months to monitor the effectiveness of the treatment.

The blood test should be performed after fasting overnight.

Procedure for LDL test

An LDL test requires only a clear sample of blood. This could also be called a venipuncture or drawing blood. It’s commonly done in the morning after 12 hours of fasting.

The healthcare provider will start by applying antiseptic to the region from where the blood will be drawn. Normally, blood is drawn from a vein in your elbow fold or at the back of your hand.

The medical professional will then tie an elastic band around the upper arm. That makes blood accumulate in the vein. A sterile needle is inserted into your vein, and blood is drained into a tube. You may experience mild to moderate pain that resembles a burning or piercing sensation. The discomfort will normally be lessened by calming your arm when the blood is being drawn.

A bandage will be applied to the wound once he/she is finished drawing blood. Pressure should be applied to the wound to help stop bleeding and prevent bruise. The blood is sent to a medical laboratory for LDL levels to be measured.

Learn more about cholesterol management, here.



BMI Calculator

Use this calculator to check your body mass index (BMI) and find out if you're at a healthy weight. You can also use this tool to check your child's BMI.



Hello Health Group does not provide medical advice, diagnosis or treatment.

LDL: The "Bad" Cholesterol https://medlineplus.gov/ldlthebadcholesterol.html Accessed on 29/02/2020 LDL Cholesterol https://www.webmd.com/heart-disease/ldl-cholesterol-the-bad-cholesterol#1 Accessed on 29/02/2020 Medical Definition of LDL (low-density lipoprotein) https://www.medicinenet.com/script/main/art.asp?articlekey=6232 Accessed on 29/02/2020 HDL (Good), LDL (Bad) Cholesterol and Triglycerides https://www.heart.org/en/health-topics/cholesterol/hdl-good-ldl-bad-cholesterol-and-triglycerides Accessed on 29/02/2020 Cholesterol Guidelines & Heart Health https://my.clevelandclinic.org/health/articles/16866-cholesterol-guidelines--heart-health Accessed on 29/02/2020 Cholesterol Numbers: What Do They Mean https://my.clevelandclinic.org/health/articles/11920-cholesterol-numbers-what-do-they-mean Accessed on 29/02/2020 Low-Density Lipoprotein Cholesterol (LDL-C): How Low? https://www.ncbi.nlm.nih.gov/pubmed/28245773 Accessed on 29/02/2020 Circulating low density lipoprotein (LDL). https://www.ncbi.nlm.nih.gov/pubmed/30059347 Accessed on 29/02/2020
Picture of the authorbadge
Written by Nikita Bhalla Updated Apr 05, 2021
Fact Checked by Hello Doctor Medical Panel