Risk factors for pulmonary embolism and other dangerous types of blood clots include a family history of blood clotting disorders, being on extended periods of bed rest, pregnancy, smoking, and obesity. But one other thing may increase your risk of a dangerous blood clot, according to an April 2021 study done in Sweden. People with one blood type in particular may be at higher risk of developing a blood clot, they say. Read on to find out what it is, and how to lower your risk no matter what blood type you have. READ THIS NEXT: Wearing This Increases Your Blood Clot Risk, Experts Say. Not sure what your blood type is? Your parents’ blood type may provide a clue. That’s because your blood type is inherited from them, passed down genetically, says Penn Medicine. Determined by proteins in your red blood cells called antigens, there are four main blood types: A, B, AB, and O. The Rhesus, or Rh, factor, may be either positive or negative for each type, meaning there are eight possible blood types. Thirty-seven percent of the population has O+ blood, making it the most common type (and the highest in demand at blood banks), according to the American Red Cross. READ THIS NEXT: Hailey Bieber Says This Was the First Sign of a Blood Clot in Her Brain. While it’s true that blood types generally fall into one of the eight categories previously mentioned, scientists said this month that they’ve discovered a new group of blood types. Per CNN, a study published in the journal Blood described a blood type called the “Er blood group,” which can cause immune cells to attack other cells. “The Er antigen was discovered years ago, but the study is the first to describe different mutations of the antigen,” they reported. While this blood type is rare, researchers say it could be important for healthcare providers to be aware of “if they are having trouble diagnosing their patient.” A Swedish study, published in the April 2021 issue of the journal eLife, looked at the link between blood type and over a thousand different diseases and found that people with type A blood were more likely to develop PE and portal vein thrombosis (PVT)—another potentially deadly type of blood clot. PVT is especially scary because, as Healthline reports, it often has no symptoms. “Although PVT is treatable, it can be life-threatening,” they write, adding that the risk factors for PVT include liver disease, inflammation of the pancreas, appendicitis, and trauma or injury. One in three people have A+ blood, the American Red Cross says, while one in 16 have A- blood, making type A blood overall one of the more common blood types. For more health news sent directly to your inbox, sign up for our daily newsletter. While the idea of developing a blood clot is scary, you can take action to lower your risk—no matter what your blood type is. Verywell health says the most important thing you can do to reduce your chance of a life-threatening blood clot is to stop using tobacco products, if you’re in the habit. Other lifestyle changes you can make include getting plenty of exercise—walking counts!—as well as maintaining a healthy weight, eating less salt, and taking your medications as prescribed.ae0fcc31ae342fd3a1346ebb1f342fcb Speak with your healthcare provider if you’re concerned about blood clots, and to find out whether you’re at risk due to your blood type or other factors. If you don’t know your blood type, you can also ask them to tell you, or to test you if it’s not already part of your medical record.