The holidays are a time for family and friends, but they can also be filled with pressure and stress.
Mary Kennedy knows how stressful they can be.
"There's all the shopping for the kids, the grandkids. And cooking and baking and it's always a lot of work," she said.
In the midst of all the hustle and bustle of the holidays three years ago, the 81-year-old had a massive heart attack.
"I got out of bed and I thought - I'm in trouble. I couldn't breathe properly. I didn't have any pain but I had pressure on my chest," she said.
Mary called 911 and was transported to Pomona Valley Hospital Medical Center. She had what doctors call a "widowmaker."
"One of her arteries was completely blocked and before she could get to the cath lab, her heart stopped," Dr. Nitanth Vangala said.
Doctors cleared the blockage and now, Mary is better than ever. But her case is not unusual when it comes to having a heart attack during the holidays.
A new British Medical Journal study finds this time of year is associated with a 15 percent higher heart attack risk. Vangala, who is an interventional cardiologist, said during this time of year, people sometimes skip their meds and their doctor appointments.
"We tend to become a little bit looser when it comes to our lifestyle changes," Vangala said. "So I think a lot of these put together tend to lead us to have more incidents of heart attacks."
But the day with the highest likelihood of a heart attack? Christmas Eve. Researchers found a 37 percent increased risk of heart attack, peaking at around 10 p.m.
Scientists in the study believe it's most probably triggered by emotional stress. Vangala agrees.
"I do think stress is an underappreciated risk factor," he said.
So what's the best strategy to stay heart healthy during the holidays? Vangala advises trying not to get sick by frequently washing hands and getting enough sleep. He suggests staying active and says to take it easy when you celebrate.
"You don't want to eat excess salt. You don't want to drink excessively. You want to do all these things in moderation and really be responsible," he said.
These days Mary does most of her shopping online. And while family can be a source of stress, she said they're also a source of joy.
"Merry Christmas," she said. "And just thank God for you and your family."