Everything you need to know about photoplethysmography (PPG), the technology behind heart rate measurements in fitness watches and smart rings. When you purchase through links on our site, we may earn ...

A leaky heart valve occurs when a heart valve doesn’t close properly, allowing blood to flow backward. During pregnancy, this condition can affect circulation and increase strain on your heart. A ...

Dr. Paul Friedman answers the question: 'Heart Block versus Artery Blockage?' — -- Question: I have been diagnosed with heart block. How does this differ from blockage in one of my arteries?