Track whether or not you get short of breath while walking. This could be walking down the street or it could be walking up stairs, but you struggle to make it the whole way without gasping for air. It could be asthma or a cold, but it could also be a sign your heart is in trouble. Fluid that builds up in the left side of the heart can cause coughing. This is easily treatable and, once you get it fixed, chances are promising that you’ll never experience it again. While exercise promotes a healthy heart, don’t wait to get this symptom checked out. It could save your life.