Is Lipoprotein(a) Increasing Your Risk for Heart Disease?

When your provider checks your cholesterol levels, you will usually get a reading of your HDL, LDL, and triglyceride levels. But there are other cholesterol particles in the blood that standard cholesterol tests do not always measure — like lipoprotein(a), or Lp(a). 

Researchers know less about Lp(a) than other types of cholesterol. But high Lp(a) affects about 20% to 30% of the world population. And a high level is linked to a greater risk for heart attacks and strokes. In this article we’ll go into more depth about Lp(a), its connection to heart disease, and whether you should consider having yours tested.

What is lipoprotein(a)?

Lipoproteins are particles in the blood that carry cholesterol. The main types of cholesterol are HDL (high-density lipoprotein) and LDL (low-density lipoprotein). In general, HDL is considered good for you, and LDL cholesterol is considered bad for you. 

Lp(a) is a type of LDL cholesterol. Because of its chemical structure, it’s very “sticky.” That means it can easily stick to the walls of the arteries. High LDL levels are linked to blocked arteries that can cause cardiovascular disease.

Your lipoprotein(a) level is largely determined by your genetics. But researchers are still trying to understand exactly which genes are involved and how other factors may affect how those genes behave in the body. 

There is also evidence that chronic inflammation — like from autoimmune conditions or chronic infections — may also raise Lp(a) levels. But the effect is likely much smaller than genetics.

Why is lipoprotein(a) bad for you?

If you have a high level of Lp(a), your risk of several heart and blood vessel conditions is higher than average. This is one reason heart troubles can run in families even when all other risk factors are low. 

Here’s a rundown of how Lp(a) can affect your health.

Cardiovascular disease

Over time, Lp(a) can get stuck in the heart arteries and cause the blood vessels to narrow. This can cause symptoms of chest pain, or angina. It can also put you at risk for a heart attack. 

Lp(a) can also cause narrowing in the blood vessels that feed other parts of the body — like the brain. High levels raise the risk for stroke. It can also lead to blockages in the arteries that supply blood to the kidneys and legs.

Blood clots

Lp(a) seems to make the blood stickier. This is why someone with high Lp(a) has a mildly increased risk for blood clots. 

Clots often begin in the legs, where they can cause pain and swelling. But they can travel to the lungs and cause pulmonary embolism, which can be life-threatening. There’s not a lot of research on Lp(a) and blood clots. The effect appears to be fairly small, but it’s still important.

Heart valve problems

High Lp(a) can also lead to aortic stenosis. In this condition, the aortic valve does not open well. This is due to stiffening and thickening of the valve. Medication can’t fix this, so people with this condition sometimes need to have their aortic valve replaced.

This is why if you have a high Lp(a), it’s especially important to pay attention to any unexpected symptoms. These can include: 

• Chest pain 

• Sudden weakness or numbness in the body

• Shortness of breath 

• Swelling in the legs

• Heart palpitations

How do you measure lipoprotein(a)?

A blood test can measure Lp(a). It’s not included in most cholesterol tests, so your provider has to order it. But they can use the same blood for this test. 

Most of the time there’s no reason to recheck Lp(a) once you know your number. That’s because the level is mainly related to genetics. Usually Lp(a) doesn’t change much over time.

What is a normal lipoprotein(a) level?

Lp(a) tests can be reported in mg/dL or nmol/L. This can be confusing because the numbers are different. Your Lp(a) is high if it is over 100 nmol/L or over 50 mg/dL.

Since genetics mostly determine Lp(a), the average level varies among races: 

• The average Lp(a) for white Americans is 20 nmol/L. 

• Black Americans tend to have higher levels, with an average of 75 nmol/L. 

Who should check their lipoprotein(a) levels?

People who have a family member with heart disease sometimes choose to get tested. This is especially true if that family member had no known risk factors for heart disease. Technically speaking, someone has a “family history” when they have:

• A male family member who was diagnosed with heart disease before the age of 55

• A female family member who was diagnosed before the age of 65

Someone may also choose to get tested if they have been diagnosed with a blocked artery and have no or few risk factors. In this scenario, a test for Lp(a) could help identify a possible cause. 

And, of course, anyone can ask their provider to test their Lp(a) level. But your insurance may not cover it if you don’t have the above risk factors.

Why trust our experts?

Written by:

Sarah A. Samaan, MD

Sarah Samaan, MD, FACC, FACP, FASE is a board-certified cardiologist who practiced clinical cardiology for nearly 30 years. She is a member of the American College of Cardiology, the American College of Physicians, and the American Society of Echocardiography.

Edited by:

Katie E. Golden, MD

Katie E. Golden, MD, is a board-certified emergency medicine physician and a medical editor at GoodRx.

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