READ THIS NEXT: If Your Legs Feel Like This, Get Your Heart Checked. The term “heart failure” is a bit misleading, in that the name implies a sudden onset condition. In reality, heart failure can build gradually over time, causing progressive complications to your cardiological health. Despite its dire name, it can even go completely overlooked for some time. Heart failure occurs when weakened heart muscles fail to pump blood as efficiently as they should. This causes blood to back up into the heart’s chambers and fluid to pool in the lungs and the legs. This can lead to a range of unexpected symptoms, some of which may appear only tangentially related to heart health. READ THIS NEXT: Not Doing This Before Bed Could Be Hurting Your Heart, Experts Warn. Several important symptoms can signal heart failure, the Mayo Clinic says. These include fatigue and weakness, rapid or irregular heartbeat, reduced ability to exercise, swelling in the feet, ankles, and legs, persistent cough, wheezing, abdominal swelling, nausea, chest pain, rapid weight gain, and difficulty concentrating.ae0fcc31ae342fd3a1346ebb1f342fcb Experts say one more crucial symptom is among the most common signs of heart failure—and is also among the easiest symptoms to overlook. According to Rigved Tadwalkar, MD, a board-certified cardiologist at Providence Saint John’s Health Center in Santa Monica, California, shortness of breath is extremely common in heart failure patients—but is far too often overlooked. “While shortness of breath is a symptom that can be associated with a number of conditions, progressive shortness of breath, especially when associated with bloating, leg swelling, weight gain and fatigue might indicate that the heart is failing,” he tells Best Life. “The symptoms often start subtly and progress slowly, so it can take time for some individuals to realize that something is wrong.” Tadwalkar adds that “listening to your body is important.” If, for instance, you notice that you need to stop frequently during physical activities due to shortness of breath, this should be a hint that it’s time to call the doctor. For more health news sent directly to your inbox, sign up for our daily newsletter. People tend to overlook shortness of breath for one of several reasons, says Yu-Ming Ni, MD, a cardiologist at MemorialCare Heart and Vascular Institute in Fountain Valley, California. Sometimes, he says, people ignore this symptom because it only occurs when they’re lying down. This happens because when you lie down, fluid backs up into the lungs. “The solution to this for many people is using more pillows, or sleeping in a recliner,” Ni says. “So if you find yourself needing more pillows to sleep comfortably, or using a recliner to sleep, consider seeing a doctor to get checked for heart failure. Don’t blame the bed!” Other times, patients may blame their discomfort on normal aging or other underlying illnesses. “The incidence of heart failure increases with age so some people may misattribute this symptom to simply getting older,” says Tadwalkar. “What’s more, many individuals have other medical problems that cause shortness of breath and may feel that it is an existing issue causing the problem instead of heart failure.” Rather than attempting to diagnose yourself, you should always see a doctor if you experience persistent shortness of breath.