Before you blow off heart disease as something health-savvy younger women don't have to worry about, read the stats. It's the No. 1 killer of men and women over age 20, and one in three women have already racked up damage without having a clue. Here are eight tips you should know to help your heart.

Learn your family history

Like so many other conditions, your genes influence your heart disease risk. If a first-degree female relative (your mom or your sister) was diagnosed with heart disease before age 65, or a first-degree male relative received a diagnosis before age 55, your odds of having a heart attack someday increase threefold.

Stop smoking — for good

As if you need another reason to ditch the habit, women who smoke more than double their risk of sudden cardiac death, according to a December 2012 American Heart Association study, because nicotine can alter heart functioning and cigarette smoke scars heart tissue. We're not just talking about pack-a-day puffers here. Any amount of smoking boosts your risk, the study explains, even an occasional cigarette at a party. The upside: As soon as you go cold turkey, your heart will start rebounding.

Get a cholesterol test

It's a simple screening that can clue you in to your future heart disease risk. Get tested in your 20s so you have a baseline, and if it's in a healthy range, you won't need to be retested for another five years. If the numbers aren't optimal, your doc can help bring them in line by recommending diet changes or prescribing medication.

Move around

Your heart is a muscle, and like all muscles, working it out keeps it healthy by strengthening tissue and improving circulation. Aim for about 30 minutes a day of light to moderate cardio. That doesn't mean hightailing it to Crossfit every night: You can reap the benefits with activities such as dancing, cleaning your house or even walking your dog.

Reel in stress

When you're anxious, your body pumps out higher amounts of the hormone cortisol, and consistently high cortisol levels crank up your cardiovascular disease risk.

Also, a small 2012 study from Penn State University found that when women were stressed, their hearts pumped less blood than stressed-out men, putting more of a strain on the female heart. We know it's easier said than done, but try to carve out time every day to unwind, even if it's just chilling with your iPod or popping in a yoga DVD.

Watch what you eat

Unprocessed, plant-based foods have a positive effect on your heart, so load up on plenty of salad, whole grains and cereals. Keep sugar and salt to a minimum; simple sugars (the kind found in processed foods and snacks) have been linked to higher levels of triglycerides, which contribute to heart disease. Excess salt also poses a threat; too much can boost blood pressure, which stresses the heart. Of course, just as important as what you eat is how much you consume. Controlling portion sizes keeps you from packing on pounds, and obesity is a cardiovascular disease risk factor.

Score regular restful sleep

Sleeping less than an average of seven hours a night has been shown to cause high blood pressure. Poor sleep is also linked to the accumulation of abdominal fat — and muffin top is another heart attack offender.

Strengthen your social network

Whether it's in real time or on Facebook, people who maintain positive relationships with friends and relatives have better heart disease odds. One reason has to do with the fact that a strong social network makes it easier to handle life's challenges. But people who are socially isolated also tend to skip workouts and eat poorly.