Last Updated: 28/01/2026
Why Do Cats Purr?
Does your cat purr when they are happy, or is there more to the story? Our vet team explores the fascinating reasons why cats purr, how they create the sound, and the incredible health benefits these vibrations offer for both cats and humans.
Author: Dr Carla Paszkowski BVSc (Hons)
Reading Time: 5 minutes - short read
There is nothing quite like the soothing, rhythmic rumble of a cat curled up in your lap. For most pet parents, a purr is the ultimate "five-star review," signalling a very happy and relaxed feline. However, as many of us have noticed at the vet clinic, cats also purr when they are nervous, in pain, or even recovering from an injury. This suggests that purring is far more than just a smile in sound form; it is a complex communication tool and a clever biological mechanism for self-healing. Let’s dive into the science behind these vibrations and what your cat might be trying to tell you.
The main reasons: why do cats purr?
Cats purr when they are content, happy, relaxed, but they may also purr when they are sick or stressed. Purring has self-soothing effects on cats and releases endorphins. Purring is more a muscular tremor as opposed to voluntary vocalisation.
Understanding the "hungry purr": communication and solicitation
Kittens first start purring when they are suckling. Because they cannot meow while feeding, they can purr and so use this as a way of communicating with their mother. The mother cat will purr back to her young as encouragement.
Some cats retain this behaviour as adults and purr when they are eating, while some cats have a special "I'm hungry" purr. Cats who purr when they're hungry usually emit high pitched cries of a similar decibel to a human infant. Some scientists have described this behaviour as exploitive as it triggers our nurturing instincts to feed them faster.
Why do cats purr when they are stressed or in pain?
Purring has been observed in cats experiencing stress, injury or fear. It appears to be a coping mechanism cats use to comfort themselves and other injured animals. In a way, purring is the kitty equivalent of a lullaby.
Did you know: Big cats like cheetahs, panthers and tigers purr just like domestic cats in similar situations.
How do cats make the purring sound?
In terms of what you feel, that bubbling massage is the rhythmic vibration of the larynx muscles contracting and relaxing quickly.
When contracted, the muscles reduce the amount of air that can flow through the larynx and during inhalation or exhalation we hear the purring noise.
Every cat has their own unique purring pattern, volume and frequency. The volume of a purr is comparatively low and designed for close range recognition as opposed to other vocalisations. Though some very special cats still manage a purr as loud as a lawnmower which might not be the best way to wake up on a Sunday morning.
Health benefits of cat purrs for humans
Not only can purring help with our kitties mental state but studies show that it does affect them physically. The tremor caused from purring applies a gentle rhythmic pressure to the bones which actually helps to strengthen them. Just as muscles get stronger when you use them, so do bones.
This discovery has inspired research into human technologies. Loss of muscle mass and bone density is seen in low gravity environments. Manipulating tremor behaviour can be used for astronauts to maintain muscle mass and bone density during space voyages.
There are claims that being near a purring kitty can also be beneficial to humans in relieving stress, reducing blood pressure and stimulating bone or muscle repair. Studies have shown that owning a cat can reduce your risk of a stroke by almost one third.
So next time your kitty decides to lie on your chest and purr loudly in your ear at 2am, maybe just go with it. Cause now you know, it may save you in the long run!
FAQs
Whether your feline friend is seeking a snack, soothing themselves during a thunderstorm, or simply enjoying a cuddle, the purr remains one of nature’s most versatile tools. It is a remarkable blend of communication and physical therapy that strengthens their bones and lowers our blood pressure. So, the next time your cat settles in for a loud purring session, take it as a compliment to your bond - and a little free health boost for you both.
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History
Our experts continually monitor the health and wellness space and we update our articles when new information becomes available.
Thu 29 Jan 2026
Edited by Dr Gillian Hill BVSc (Hons)Dr Carla Paszkowski BVSc (Hons)
Veterinarian
Dr. Carla graduated from the University of Queensland in 2013 with a Bachelor of Veterinary Science and worked for a number of years in small animal clinics across South East Queensland. While Carla enjoys most facets of clinical veterinary work, she holds a special passion for feline medicine, pocket pets, and nutrition.
