Lp(a): The Inherited Heart Risk You've Never Measured
By: Joy Stephenson-Laws, JD, Founder
You can have a "normal" cholesterol panel and still be carrying a serious, inherited heart risk that the panel never looked for. Its name is lipoprotein(a), written Lp(a) and said out loud as "L-P-little-a." In March 2026, for the first time in an ACC/AHA guideline, the American College of Cardiology, the American Heart Association, and nine other medical groups recommended that every adult have it measured at least once.
If you'd rather catch a problem early than be surprised by it, this is the test to ask for.
What Lp(a) actually is, and why it does double damage
You already know LDL, the "bad cholesterol" that builds up in artery walls. Lp(a) is an LDL-like particle carrying one extra piece: a protein called apolipoprotein(a), or apo(a), attached to it. That attachment is what makes Lp(a) more harmful than ordinary LDL, and it does damage in two well-established ways.
The first is the familiar one. Like LDL, Lp(a) drives cholesterol into the walls of your arteries and builds the plaque that narrows them.
The second is inflammation. Lp(a) carries oxidized fats that inflame the artery wall and the heart's aortic valve, stiffening the valve and speeding the damage over the years. Particle for particle, that inflammatory punch is part of why Lp(a) appears more dangerous than regular LDL.
There may be a third route. The apo(a) piece closely resembles plasminogen, the protein your body uses to dissolve blood clots, so researchers have long suspected Lp(a) tilts the body toward clotting. That idea is biologically plausible but not yet proven in people, so treat it as a question scientists are still working out rather than a settled fact.
So Lp(a) isn't simply more bad cholesterol. It's an inherited, LDL-like particle tied to plaque and inflammation, with a possible clotting effect still under study.
Why you only need to measure it once
This is the part that surprises people. Your Lp(a) level is set mostly by inherited variation in a single gene, the LPA gene, that you were born with. Roughly 80 to 90 percent of it is genetic. Diet barely touches it. Exercise barely touches it. Even statins, which lower ordinary LDL well, don't meaningfully lower Lp(a).
That isn't a reason to ignore it. It's the reason that, for most people, one measurement is usually enough. Unlike your LDL or your blood pressure, which drift and need watching, your Lp(a) is closer to a fixed coordinate. You learn where you stand one time, then account for it for the rest of your life. (A few situations, like pregnancy, thyroid disease, or kidney or liver problems, can shift the number, so your clinician may occasionally retest.)
At pH Labs we keep coming back to a simple idea: observation is data, interpretation is a hypothesis. Lp(a) is a clean example. For decades it was data nobody collected, so a whole layer of inherited risk stayed invisible. The new guideline is, in plain language, finally saying: take the observation.
What counts as high
Risk rises gradually as Lp(a) climbs, but the guideline treats a level at or above 125 nmol/L, which is roughly 50 mg/dL, as the point where it becomes a meaningful risk factor, raising long-term heart-attack and stroke risk by about 1.4 times. At 250 nmol/L, about 100 mg/dL, the risk roughly doubles. Labs report Lp(a) in two different units, so check which one your result uses before you compare it to anything.
One detail makes this test matter for your whole family, not just you. Lp(a) is strongly inherited, so a high result is useful information for your blood relatives. In a large UK Biobank study, about 47 percent of the first-degree relatives of someone with high Lp(a) also had high Lp(a), compared with roughly 16 percent of unrelated people. That's why clinicians recommend cascade screening: once one person turns up with an elevated level, their parents, siblings, and children are worth testing too. One test can protect several people.
What else changed, for those who want the fuller picture
Lp(a) is the headline, but the 2026 guideline reset several things a proactive person should know.
Cholesterol goals are back, with actual numbers. The 2018 guideline leaned on statin intensity and percentage reduction more than fixed LDL targets. The new one brings the targets back. For primary prevention, the goal is generally an LDL under 100 mg/dL at low, borderline, or intermediate risk, and under 70 if you're high risk. (People who already have heart disease have lower goals still.) The logic is "lower for longer." Plaque builds from your accumulated lifetime exposure to LDL, so holding a lower number for more years means less total damage.
The risk calculator got better. For primary prevention in adults ages 30 to 79 without known heart disease, clinicians now use a tool called the PREVENT equations instead of the older one. It folds in kidney and metabolic health, gives both a 10-year and a 30-year estimate, and no longer uses race as an input. The older calculator did, and that had been criticized for treating race as if it were biology.
You can usually skip the fasting. For routine lipid checks, a nonfasting sample is now acceptable. Fasting may still be preferred in a few cases, such as known or suspected high triglycerides, or a family history pointing to an inherited lipid disorder. For most people, though, that removes a common excuse to keep putting the blood draw off.
It starts young. The guideline supports cholesterol screening in childhood, between ages 9 and 11, then again around age 19, and at least every five years after that. Heart disease doesn't begin the year it gets diagnosed.
What a proactive person actually does with this
Ask for a one-time Lp(a) test. It's a simple blood draw, and most people have never had it. Don't let worry about what it might show keep you from finding out. The number is just information, and you can't act on something you've never measured.
Get your standard numbers and learn your personal LDL goal, which depends on your risk rather than on a single cutoff that applies to everyone.
If your Lp(a) is high, don't panic, and don't treat the number as a verdict. What you can do is real and worthwhile: drive down every other risk factor you can control, because a high Lp(a) raises the stakes on everything else. Get your LDL low, keep your blood pressure in range, don't smoke, and stay ahead of your blood sugar.
Tell your blood relatives your result. This is the rare test where your number is also useful information for the people who share your genes.
A high number is information, not a sentence. Let yourself feel the jolt, then pause long enough to ask what it's really telling you to do, then act on what you can change. That pause is where the value lives. It turns a frightening result into a to-do list instead of a verdict. Feel, pause, act. A lab value that moves you to lower your other risks has done its job.
The bottom line
The most useful sentence in a long, technical guideline is a short one: every adult should know their Lp(a), once. It's inherited, it's been invisible, and it may be the missing piece in a cholesterol picture you assumed was complete. Ask for the test, learn your number, and bring your family along.
(This article is for education and isn't a substitute for care from your own clinician. Your numbers and your goals are personal, and they deserve a real conversation).
Joy Stephenson-Laws, JD, is the founder of Proactive Health Labs, a national nonprofit that provides free, evidence-based health education, and the author of Your Labs Are Fine. You're Not. Her work helps people become active, informed partners in their own care
Sources
2026 ACC/AHA/Multisociety Guideline on the Management of Dyslipidemia. Published in JACC (doi:10.1016/j.jacc.2025.11.016) and Circulation (doi:10.1161/CIR.0000000000001423), March 13, 2026.
American College of Cardiology. "ACC, AHA Release New Clinical Guideline for Managing Dyslipidemia," March 13, 2026.
American Heart Association. "ACC/AHA Issue Updated Guideline for Managing Lipids, Cholesterol," March 13, 2026.
Kronenberg F, Mora S, Stroes ESG, et al. Lipoprotein(a) in atherosclerotic cardiovascular disease and aortic stenosis: a European Atherosclerosis Society consensus statement. European Heart Journal. 2022;43(39):3925-3946.
Reeskamp LF, Tromp TR, Patel AP, et al. Concordance of a High Lipoprotein(a) Concentration Among Relatives. JAMA Cardiology. 2023;8(12):1111-1118. doi:10.1001/jamacardio.2023.3548
