27 Weird Facts You Never Knew About Your Heart

You know you can’t live without your heart’s daily thud-thud. But did you know that it will beat more than 2.5 billion times in your lifetime?

Here, 27 more fascinating facts about the engine that powers your entire body.

Your heart is about the size of two fists and weighs 10 ounces, or slightly less than a can of soda. Each valve—the parts that open and close to allow blood to flow in and out—is about the size of a half-dollar.

Each day, your heart beats about 100,000 times. Over a 70-year lifetime, that adds up to 2.5 billion pulses.

Your workouts not only boost your heart health, they can also serve as your body’s “check engine” light. 

If you spend a few sessions in a row struggling to run the same pace or complete the same circuit you usually do for no apparent reason, talk to your doctor. 

This could signal that your heart’s not quite pumping enough blood, which is an early sign of heart trouble, says Allan Stewart, M.D., director of aortic surgery and codirector of the valve center at The Mount Sinai Hospital in New York.

Related: Why You Could Be Days Away From a Heart Attack—and Never Know It

Heart cancer develops so rarely even the Mayo Clinic sees only about one case per year. That’s because heart cells stop dividing early, so cancer-causing mutations are less likely to occur. 

Still, that’s not to say that cancer elsewhere in your body can’t harm your heart. Other cancers can metastasize, or spread, to your heart. Plus, chemotherapy and other treatments for malignancies can damage its tissue.

Related: The Top 10 Cancer Signs You Shouldn’t Ignore

If you go to your doctor because you can’t get or maintain an erection, you’ll probably get a heart test, too. 

Erectile dysfunction serves as an early red-flag for heart problems. That’s because the tiny blood vessels in the penis can sustain damage before larger veins and arteries. 

Related: The Men’s Health Guide To Erectile Dysfunction—Everything You Need to Know to Keep Your Erection Hard For Life

Men who have sex twice a week or more appear less likely to develop heart disease than those get busy once a month or less, according to a study in the American Journal of Cardiology. 

Related: 5 Exercises That Make You Better At Sex

Scientists think there may be two possible reasons behind the diminished risk: a good romp can count as a mini-workout, or frequent sex with the same partner is the sign of a solid, stress-relieving partnership—both of which are proven to improve heart health. 

Laughter balances your stress hormones, reduces inflammation in your arteries, and increases HDL or “good” cholesterol. These effects last at least 24 hours, according to the American Heart Association. 

For a quick check of your heart risk, wrap a tape measure around your waist. If it measures half your height or more—say, 35 inches or greater for a 5’10” guy—your middle makes you prone to problems, Dr. Stewart says. 

Fat stored in your gut—especially deep or visceral fat, the stuff surrounding your organs—secretes hormones and other compounds that boost your chances of heart disease.

Alcohol—especially red wine—contains antioxidants and a compound called resveratrol. So drinking it in moderation, up to two drinks per day and no more than 14 per week for guys, may protect your heart against artery damage. 

Related: Why You’re a Jerk When You Drink Alcohol

While two glasses of wine helps your heart, binge drinking regularly places your heart in peril. 

College students who regularly downed more than four drinks in two hours sustained changes in their blood vessel cells that left them prone to hardened arteries, according to a study in the Journal of the American College of Cardiology. And that can eventually lead to heart attack.

One cardiac cycle—the contacting and relaxing of your heart muscle, or what we think of as a beat—takes about 0.8 seconds.

You might put your hand on the left side during the national anthem, but your heart actually rests in the center of your chest, right below your sternum. It’s just tilted slightly to the left, says UC San Diego cardiac electrophysiologist Amir Schricker, M.D.

Related: 7 Lies You’ve Been Told About Your Own Body

Doctors continue to develop minimally invasive treatments for heart disease, heart attacks, and related conditions. “Within a generation, the concept of cracking someone's chest open to fix their heart is going to be something we look upon as barbaric,” Dr. Stewart says.

Even sooner—within two to three years—repairing your heart valves with a small incision and a thin wire called a catheter won’t even require a hospital stay, he notes. 

If you stretched out all your blood vessels, they’d extend more than 60,000 miles long and wrap around the world more than twice. 

You have about six quarts of blood in your body right now. During the average lifetime, your heart will pump about 1 million barrels of the stuff.

More hospitalizations for heart problems occur on days with higher levels of large air particles, Johns Hopkins researchers found.

And serious heart attacks strike more people who already have heart disease on bad air days, research from the Intermountain Medical Center Heart Institute showed.

Related: The Hidden Danger At Your Gym

Most heart attacks begin with symptoms far more subtle than crushing chest pain, Dr. Schricker says. Signs people often overlook include a heartburn-like tightness in the chest, shortness of breath, nausea, or pain in the jaw or arm. 

Related: 100 Ways to Protect Your Heart

Another cardiovascular red flag: stepping up a shoe size. 

When your heart starts to fail, your body retains water, causing swelling in your legs and feet, Dr. Stewart says. That may make your regular-size shoes feel too tight.

Doctors once had to put their ears directly on patient’s chest to hear their hearts. In 1816, a French physician named Rene Laennec rolled up a thick sheet of paper to create the first stethoscope, placing one end to his ear and the other to his patient. 

A two-eared version similar to what doctors use today, made partly of natural rubber, was made in 1851.