15 Heart Murmur Symptoms That May Indicate Serious Issues
3. Diaphoresis: Unwarranted Sweating Without Exertion

Excessive, cold sweating without physical exertion (diaphoresis) is an often-overlooked yet critical warning sign of a strained heart. When the heart struggles to pump blood efficiently, the body activates its "fight-or-flight" response, releasing adrenaline. This can trigger profound sweating, often accompanied by clammy skin and a rapid heartbeat. In infants with congenital heart defects causing murmurs, this can be particularly concerning. Such unprovoked sweating signals the heart working overtime, potentially on the brink of failure or experiencing significant distress.
4. Edema: Unexplained Swelling in Extremities or Abdomen

Fluid retention, manifesting as swelling (edema) in the ankles, feet, legs, or even the abdomen (ascites), is a stark warning sign linked to severe heart murmurs. This occurs when the heart's pumping power is insufficient to return blood efficiently from the extremities, causing fluid to leak from blood vessels into surrounding tissues. In children, this can also present as swelling in the face. This insidious symptom indicates the heart's inability to manage the body's fluid balance, often pointing to congestive heart failure.