With a powerful enough amplifier, an electric guitar can reach volumes that are uncomfortable or even painful to hear. For this reason, it's important to be careful when playing an electric guitar at high volumes, especially in close quarters.
In general, the louder an electric guitar is played, the more distorted the sound will become. This is because the amplifier's tubes or transistors are working harder to amplify the signal, which causes the sound waves to become more compressed.
At extremely high volumes, the sound of an electric guitar can become almost completely distorted, resulting in a sound that is harsh and unpleasant.
For most situations, it's not necessary to play an electric guitar at extremely high volumes. However, if you're playing in a band or other musical group, you may need to turn up the volume to be heard over the other instruments.
In any case, it's important to use your ears and be aware of the volume levels that you're playing at. If you start to feel pain in your ears, it's time to turn down the volume.