Why is my cat vibrating?

It all starts in the kitten's brain: a neurological signal is sent repeatedly to the feline's larynx muscles, causing them to contract at a rate of 25 to 150 vibrations per second. Thus, when the kitten breathes, the air that passes through its vocal cords produces the comforting purring sound.

Like meowing, purring is a way that felines use to express their feelings. Usually the cat purrs when it expresses feelings of tranquility, pleasure and safisfaction. However, it can also emit sound by vibrating the vocal cords when it is angry, painful or hungry.

It has a medical condition that it might grow out of but may not