The explanation as to why cats purr has recently been a subject of much controversy. Some have suggested cats only purr when they are alone, if truth be told I have no idea if cats purr only when they are alone, it does seem likely that they do, if one understands a little about why cats purr.
It is now known by most experienced cat lovers that cats don’t purr only when they are content and happy, they also purr during tense or traumatic moments. Cats can also purr when suddenly and violently injured. Cats are also known to purr just moments before death as it is now thought that purring releases endorphins (morphine-like-substance) which help relax the cat and ease pain. An additional new theory postulates that the range of frequency of a cat’s purr strengthens bone density and facilitates healing.
It may sound bizarre but this healing ability of a cat’s purr may also benefit humans! It is already a well known fact that the sound and vibrations of a cat’s purr helps lover humans’ blood pressure.