Photoplethysmogram

Photoplethysmogram or PPG is a big and hard word that means doctors and nurses use a special device to look at the flow of blood in your body. It's kind of like how we can see the color of your skin change if you pinch your finger really hard. The device uses a small light and it shines on your skin, and when your blood flows through your veins, the light reflects off it and creates a little graph on a screen.

The graph shows how fast and how often your heart beats. When your heart beats, your arteries expand and contract, and the device can see that change in the flow of blood. It can tell if your heart is beating too fast or too slow, and it can also show if there is a blockage in your arteries. Doctors and nurses use this to check if you are healthy or if there is a problem with your heart.