• Mayo Clinic Minute: How flu affects your heart

Amid the most intense flu season in more than a decade, a new study published in the The New England Journal of Medicine confirms that the flu virus significantly raises your risk of having a heart attack within a week of being diagnosed. The Centers for Disease Control and Prevention (CDC) still recommends all people over 6 months of age, with few exceptions, should get a flu shot.

Watch: The Mayo Clinic Minute

Journalists: Broadcast-quality video pkg (0:54) is in the downloads. Read the script.

Everyone should know that getting a flu shot helps prevent the flu. But that's not all.

"It's been shown that if you get a flu shot, it will lower your risk of having a heart attack or stroke by about 50 percent during that flu season," says Dr. Stephen Kopecky, a Mayo Clinic cardiologist.

Seriously? Yes. You see, the influenza virus can cause an inflammatory reaction all over your body. That's why you feel miserable. And, when that reaction happens, it also can irritate the lining of your arteries. If those arteries are already in trouble with plaque buildup, the inflammation can prompt a tear. A blood clot could form, blocking blood flow to your heart or brain, causing a heart attack or stroke.

"So I tell patients, get a flu shot," says Dr. Kopecky. "Not because I'm so concerned about them getting the flu, but I'm concerned about them having a heart attack or a stroke. And patients, once you tell them that, they say, 'Oh, I didn't realize that. I'll get my flu shot this year.'"