SN explained that the symptoms / signs of congestive heart failure ( CHF ) may include: Shortness of breath ( also called dyspnea ) most commonly during activity, at rest, or while sleeping, which may come on suddenly and wake you up. You often have difficulty breathing while lying flat and may need to prop up the upper body and head on two pillows. You often complain of waking up tired or feeling anxious and restless. Blood backs up in the pulmonary veins ( the vessels that return blood from the lungs to the heart ) because the heart can't keep up with the supply. This causes fluid to leak into the lungs. Persistent coughing or wheezing, coughing that produces white or pink blood - tinged mucus. Fluid builds up in the lungs. Buildup of excess fluid in body tissues ( edema ) swelling in the feet, ankles, legs or abdomen or weight gain. You may find that your shoes feel tight.