Why do you have to hold your breath during an x-ray?

It is not necessary to hold your breath during most X-rays. This was only ever required for certain types of X-rays when they first became available over a century ago, with the earliest X-ray machines producing lower-quality images that required longer exposure times. Holding one's breath helped minimize blurring caused by movement during these longer exposures.

With modern X-ray technology and faster exposure times, holding your breath is rarely needed anymore. However, there may be a few cases where it's still recommended, such as when imaging the lungs to ensure a clear image of the delicate lung structures. In such instances, the healthcare professional conducting the X-ray will provide specific instructions and guidance.