A purring cat is a fascinating experience. Cats purr mostly out of contentment, but there are times when the purr can signal distress or pain. Purr vibrations are generated at a low-frequency (25-140Hz), which is beneficial to the health of cats and humans alike. For example, when humans receive low-frequency ultrasound treatments, fractures and soft tissue (muscles, tendons, ligaments) injuries tend to heal more quickly. A cat’s purr has a similar frequency.
Kittens are born deaf and blind, so they use the purring vibrations from their mother to help them navigate the new world. On day 2, the newborn kittens are able to purr themselves. This helps them show their mother that they are happy. When mother cats give birth, they tend to purr. Purring releases endorphins which may help reduce the stress and pain of delivering kittens. Cats also purr during the end of life, which again may help control their pain and stress.