For 100 years, cardiovascular disease has been the number one killer of men, and for almost as long, high cholesterol has been linked to heart attacks, strokes, and other cardiac catastrophes.

But how early in life and how fast you need to move on cholesterol have changed. Two of the reasons: we know more now about the complicated relationship between cholesterol and heart attack risk, and we now have more precise ways to calculate your personal risk. With new guidelines to help us make sense of it all, the number of heart attacks and strokes could eventually be cut in half. Here’s what to know now.

Statins Help Sooner Than You Think

The more time your arteries spend barraged with high cholesterol, the worse off you are. That’s why doctors are now treating even mildly elevated LDL with statins. This class of meds was once typically prescribed to younger adults only when their cholesterol was dangerously high and standard lifestyle remedies — diet, exercise, stress reduction — weren’t working. But with the current focus on lowering “cholesterol years,” or how long you’re straining your arteries with even moderately high LDL, statins can play critical roles in both treatment and prevention.

“The length of exposure you have to a risk factor for heart disease and stroke is really crucial,” says UNC Health cardiologist and Men’s Health cardiology advisor Christopher Kelly, MD. “You have an intuitive sense of that with smoking — the longer and more you smoke, the more risk you have. But people hadn’t viewed cholesterol that way.” Whether you need a statin to get your LDL in a safe place depends on your other cardiovascular risk factors: if you are at a very high risk of having a heart attack or stroke, you’re going to want to keep LDL below 55 mg/dL. If your risk is considered high, you’ll want to keep it below 70 mg/dL. But if your risk is intermediate, you’re fine up to 100 mg/dL.

Yet this prevention-forward use of statins is getting pushback on social media and even from a few doctors. Some influencers are rallying opposition to Big Pharma and suggesting that doctors are overeager to prescribe — or that they receive kickbacks from doing so (they don’t). A small but vocal crowd argues, without scientific evidence, that the focus on cholesterol is misplaced, citing individuals who have high LDL and don’t have heart attacks. While some people with high LDL (100 mg/dL and over) might never have a problem, scientists have found overwhelmingly and consistently that lower cholesterol yields lower cardiovascular risk.

Lifestyle is still an important way to control LDL, but some people are just genetically prone to cholesterol problems. “You can have really high cholesterol no matter what you eat or how you look,” says Dr. Kelly. Statins have been around for decades, and they’re safe and so effective that even some cardiologists whose LDL levels aren’t technically considered high take them to reduce their arteries’ exposure to these lipids.

Your Individual Risk Determines Your Treatment

One of the more confusing things about the new cholesterol guidelines is that you may now be prescribed a statin even though your cholesterol hasn’t budged in a year. Or you and your buddy may have the exact same cholesterol numbers, but you’ve been told to go on a statin and he hasn’t.

Here’s why that’s happening: science has gotten better at figuring out how healthy your heart is going to be for how long. Using a detailed tool — the PREVENT calculator — that produces a risk percentage, doctors can see how likely it is that you’ll have a heart attack or stroke within 10- and 30-year periods. Your total cholesterol is only one number in that score, which also takes into consideration diabetes history, systolic blood pressure, and whether or not you currently take statins or hypertension medications.

These factors inform how serious you need to be with prevention, and the calculator also determines your LDL goal. It may seem complicated, but it’s actual precision medicine.

Lp(a) Is Super Important

Many doctors never test people for a type of cholesterol called lipoprotein(a), or Lp(a), because there isn’t anything you can do about it directly. The new guidelines say it’s critical to test at least once in adulthood when doing your regular blood panel. Levels of this protein are genetically determined — they don’t change throughout your life. Lp(a) behaves similarly to LDL, but its structure makes it even more likely to clog your arteries. Since you can’t bring its level down directly, you’ll want to double down on other strategies to reduce risk. “If it’s high, it shows we want to be much more aggressive with cholesterol management,” says Roger Blumenthal, MD, director of the Johns Hopkins Ciccarone Center for the Prevention of Cardiovascular Disease and chairperson of the writing committee for the new guidelines. Some drugs aimed at reducing Lp(a) are currently in clinical trials.

One more note: the guidelines say you should get your first cholesterol test between ages 9 and 11, then test every five years starting at age 19.

What to Know About Statins and Your Workouts

Statins have been blamed for causing muscle aches and weakness, but they’re the culprit less often than you’d think.

Statins can sometimes bind to a protein in muscle cells, leading to a sort of “calcium leak” into those cells. This flow of calcium can make your muscles feel weak or achy — but this happens in fewer than 10 percent of people on the medication.

More people than that, however, may incorrectly attribute their soreness to statins. Research has found statin users report muscle soreness about as often as placebo users, but they’re more likely to blame the medication. One clue that statins are actually the cause: “Aches tend to be symmetric and more often involve large muscle groups, near your shoulders (biceps/triceps) or hips (hamstrings/quadriceps),” says Ty Gluckman, MD at the Providence Heart Institute, one of the writers of the cholesterol guidelines.

If you feel achy, don’t simply stop taking the statin. “For reasons we don’t always fully understand, you may do well on one statin and not another,” explains Dr. Gluckman. “So if you don’t tolerate one, try a different statin or dosing regimen.”