Chest pain often acts as a warning system when someone is having a heart attack. But new evidence suggests that women are less likely than men to feel the telltale symptom, and as a result might be more likely to die from an undetected attack. So how can a woman best protect herself? Here's what you should know:

What could happen when a woman has a heart attack?
Tami Kimet, a 35-year-old mother of two, thought she had a flu bug. After a day of feeling unusually lethargic and sick to her stomach, she drove to a hospital to receive what she thought would be standard care. "Instead, they cut open her chest and performed a triple bypass," says Katie Moisse at ABC News. Kimet was just one of many victims to suffer a heart attack without any chest pain. And recent research suggests that it happens to more women than men.

By how much?
A major U.S. study of 1.1 million people suggests that a "surprising" 42 percent of women admitted to hospitals for what turned out to be heart attacks didn't experience any chest pain, says Anahad O'Connor in The New York Times. By comparison, about 31 percent of men failed to show the "hallmark symptom." Women put in that situation were more likely to die, too, as they were "less likely to be treated aggressively." The heart-attack mortality rate for women was nearly 15 percent, compared with 10 percent for men. 

Why are women less likely to feel pain?
It might have something to do with age, says Alice Park at TIME. "Before menopause, women may be protected by estrogen, which can counter the formation of plaques in heart arteries" — the "chief driver" of heart attacks in men and older women. But when women under age 55 suffer a heart attack, it typically isn't because of plaque. They are more prone to clot-based attacks "triggered by spasms of the heart vessels" themselves. Instead of chest pains, they feel "more generalized pain in different parts of the body, including the jaw, neck, shoulder, back, and even the stomach." 

What should a woman do, then?
Women should exercise extra caution. Other symptoms to watch out for include "shortness of breath, pressure or pain in the lower chest or upper abdomen, dizziness, lightheadedness or fainting, upper back pressure, or extreme fatigue," Dr. Nieca Goldberg from the NYU Langone Medical Center (who wasn't involved in the study) tells CBC News. Women suffering a heart attack tend to believe that their symptoms are due to less dangerous conditions like acid reflux or the flu. "They do this because they are scared and because they put their families first." 

Sources: ABC News, CBC News, NY Times, TIME