People typically interpret a cat’s purr to mean the cat is content and happy. However, there are many other ways to interpret a purr. Like all animal sounds, a purr conveys much more information than surface-level contentment – though occasionally that is exactly what the purr means. Other instances of purring that occur when cats are in pain show that there are several other meanings to a purr than just happiness and contentment. Hoping to answer the question of why do cats purr, this article explores how cats purr, the different reasons behind the purring, and the origins of cats’ purring. There are several ways to interpret a purr. From contentment to a way to fight pain, a cat’s purr is more than just a sign they are happy. It is both their communication and coping mechanism.

What Is Purring?

Before asking why do cats purr, explaining how cats purr is helpful. Strangely, experts are still not confident they know the true source of cats’ purrs.

Purring is a sound/vibration given off by cats, and experts still do not know exactly how cats do it. There are several theories, one being that purring was caused by blood flow turbulence in the chest. That theory is no longer widely believed and there are new theories being explored. One new theory experts believe to be most credible is that purring is created by the diaphragmatic and laryngeal muscles in combination with a neural oscillator. A message that originates in a neural oscillator in the brain is sent to the laryngeal muscles, which causes them to vibrate.

Their movement controls how much air passes through. Purring then occurs during inhales and exhales. Sometimes, the cat’s purr can be so quiet you will feel it rather than hear it. In other instances, the cat’s purr will be so loud you will be able to hear it from across a room. There are different reasons cats use different frequency for purring, some of which are explained below.

Why Do Cats Purr When Content?

Though there are other reasons for cats purring other than contentment, the primary reason a cat will purr is that it is happy. This is a trait they learn when they are born. A cat that is deeply relaxed or content will purr, but there are other reasons. This still begs the question, why do cats purr? This article explores varying reasons cats purr and how the instinct originated.

purring cat

Early Purring 

Cats start purring at an early age just a few days after they are born. As kittens are born blind and deaf, they communicate with their mother using purrs. The mother cat guides the kittens to her using the vibrations of the purring and the kittens purr when nursing to show their contentment. This is one reason cats purr when content – because they have been doing so since they were first born.

The kittens and the mother both experience contentment in these early stages of the kittens’ lives. They are warm, full, and safe at this time and they purr to show this contentment. The act of purring when content then stays with the cats throughout their adult lives.


Purring relaxes both the cat and any animals around the cat. As a result, when a cat is purring it is their way of settling into and creating a relaxed environment.

Endorphin Release

When cats purr, it releases endorphins. This is a quick and sure-fire way to experience contentment and explains why cats often purr when they are content. It is an endless cycle – they purr to be content and purr once they are content. The purring both creates and continues the cat’s feeling of contentment.

Possible Reasons for Cats Purring

Though cats purr when content, they also purr for other reasons. Some of these are habits that carry over from when the cats were kittens while others are more emotional. Though it is difficult to interpret a cat’s purr in given situations, the reasons listed below may provide insight into the different reasons a cat is purring.

During Labor

Cats purring through labor seems strange, especially for those who still consider purring to be caused from contentment. There is, incidentally, science behind a cat purring during labor. It is clear that a cat purring during labor is not purring out of contentment, as this is a stressful and painful moment for the cat. Rather, it is believed to help with the pain as purring releases endorphins. The endorphins released due to the purring act as a pain-reliever, which can help the cat through labor.

To Guide Kittens

Why do cats purr when they are first born? When kittens are born, they are both blind and deaf. However, they can feel vibrations. A mother’s purr leads the kittens to her, allowing them to suckle. Since kittens are not able to control and regulate their body temperature, the mother’s purr also leads them to her warm body heat. In this way, purring is crucial to the kittens’ survival.

Kittens purr when they knead on their mother to stimulate milk flow. This habit often carries over into the cat’s adult life, thus explaining why cats purr when they knead on soft surfaces, such as furniture, people, or other animals.

Emotional Reaction

Cats purr when they are feeling content, but they also purr for a variety of other emotional reasons. The cat’s purr has been compared to a human smile which on the surface conveys happiness, but can be interpreted in a variety of different ways. People may smile when happy, but also when nervous, unsure, or trying to make another uncomfortable. Similarly, cats purr for several reasons.

When trapped, a cat may purr to soothe and dissuade the potential enemy. Purring has a soothing effect on other creatures. Likewise, a cat may purr to self-soothe to calm themselves down. This technique is used when the cat is in a situation they do not see an escape from.

Pain Relief

Just as cats purr during labor, they purr in other painful situations. Cats have been known to purr in a multitude of painful scenarios, such as when sick, in pain, or near death. The primary theory regarding these purrs is the endorphin release that cats experience when they purr. This endorphin eases some pain the cat may be experiencing. Thus, rather than expressing contentment, the cat is doing almost the opposite – trying to relieve some pain they are in.

For Food

Cats are intelligent creatures, and many have learned how to maximize the effects of their purr. Not only do cats purr for themselves, but they also purr knowing the reaction it elicits from other creatures. A study at the University of Sussex in the UK discovered that cats have developed a particular, specialized “soliciting purr.”  This soliciting purr includes cries at similar frequencies to the cry of a human baby. It seems cats can ramp up this frequency to match that of the child and use this as a tactic to get their human owners to feed them.

This tactic may have originated from the cat’s early memories of being a kitten when they would communicate with their mother using purrs, and the result was always getting fed.

Healing Effects of Purring

sleeping cat

It is believed cats use purring as a healing technique. The vibrations of purrs are at 25-150HZ, which is also the frequency used to assist in bone mending and physical healing. This means a cat could purr as a health technique or an attempt to heal themselves when hurt. It may also be possible that purring during resting is a form of physical therapy for the cat. The frequency range of purring (25-150HZ) increases bone density, so the cat may use this technique to keep their bones strong and maintain their health even while resting.

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So, why do cats purr? Through many studies and observations, it is concluded that cats purr for a variety of different reasons – not just to display contentment or happiness, as many people originally thought. Though it is still unknown how cats purr, it is clear that there are many benefits to purring other than to express emotion.

The healing benefits and endorphins released when a cat purrs provide insight into an entirely new realm of reasons cats purr. A purr has healing capabilities, which can help a cat recover from injury or sickness and also help the cat maintain bone density.

Purring is a form of communication – one that is crucial when cats are first born and cannot see or hear. Purring helps kittens survive and serves as a method the mother can use for communicating with and locating her kittens.

Purring has a soothing effect and cats will use this both to soothe themselves and soothe others around them. This can be used as a defense tactic when the cat feels trapped, but also when the cat is trying to relax.

Cats use purring as a technique to get food, initially from their mother and later from their owners. Finally, cats purr when they are content. Though the alternative reasons this article has discussed may be the case, a purring cat is usually a happy cat.

Last update on 2021-03-04 at 04:43 / Affiliate links / Images from Amazon Product Advertising API