Ultrasound is a medical technology that uses high-frequency sound waves to create images of the inside of your body. These sound waves are too high-pitched for human ears to hear.

Here's how it works: A device called a transducer sends sound waves into your body. When these waves bounce off organs, tissues, or other structures inside you, they echo back to the transducer. A computer turns these echoes into moving pictures on a screen, letting doctors see what's happening inside without making any cuts or using radiation.

Ultrasound is most famous for letting expectant parents see their baby before birth, watching the tiny heart beat and limbs move. But doctors use it for many other purposes too: checking your heart's function, examining injured muscles, or looking at internal organs like the liver or kidneys to make sure they're healthy.

The technology is painless and safe. A technician spreads cool gel on your skin (which helps the sound waves travel better), then moves the transducer around while watching the screen. Unlike X-rays, ultrasound uses only sound waves, making it gentle enough to use repeatedly. Many animals, including bats and dolphins, use similar high-frequency sounds to navigate and hunt, a natural ability called echolocation.