The drug’s ability to prevent blood clots is also a double-edged sword. The body’s ability to stop bleeding is what prevents a small cut, for instance, from causing uncontrollable bleeding.
While aspirin might keep clots from blocking blood flow to our hearts and brains, it also makes it more likely that we might develop serious internal bleeds, particularly in the stomach.
“That’s not a trivial side effect,” says LeFevre. “We’re talking about people who get hospitalized” and may end up in the intensive care unit, he adds.
Some patients are more likely to suffer these complications than others; a recent review of the research reveals that men are twice as likely to experience bleeds as women, and the risk also increases with age.
Researchers estimate the risk of internal bleeding for those who take aspirin is two to four times greater than for those who don’t take aspirin at all, depending on factors such as age and overall health.
Even though people are more likely to bleed as they get older, researchers don’t think aspirin causes the risk of bleeding to build up over time. “In fact, it’s likely that if one is to bleed, their risk of bleeding is seen early on,” Berger says.
Taking ibuprofen and naproxen — common pain relievers such as Advil and Aleve — also can make bleeding more likely. Unfortunately, this kind of severe bleeding doesn’t usually come with obvious warning signs, but sudden gastrointestinal pain can be a tip-off. The bleeding is often caused by inflammation of the stomach lining or an aspirin-induced ulcer and can result in vomiting blood or blood in the stool.