Glossary

Purring

The continuous low rumbling sound many cats make when relaxed, and sometimes when hurt or frightened.

Also called: purr, cat purr, purring sound

A purr is a steady, low, humming vibration that continues as the cat breathes in and out. It is produced by rapid twitching of the muscles in the voice box, driven by a signal from the brain. Kittens can purr within their first few days of life, and it helps them tell their mother they are well and nursing. The frequency is low, roughly in the range of 25 to 150 vibrations per second.

Most of the time a purring cat is content, which is why people link the two. Cats also purr when they are anxious, in pain, giving birth or very sick, and it is thought to soothe the cat itself. Some researchers have suggested that the vibration might help healing, but this idea is not established.

Read the purr together with the body. A loose, relaxed cat that kneads and blinks slowly is happy. A cat that purrs while hiding, hunched or refusing food may be unwell. A change in the sound, such as a rattle, a loss of purring, rapid breathing or open-mouth breathing, should be reported to a vet without delay.

Last reviewed November 7, 2026

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Related terms

Kneading The rhythmic pushing of a cat's front paws against a soft surface, a habit that starts in nursing kittens and usually signals comfort. Trilling A short, rolling, rising sound cats use as a friendly greeting, copied from the way a mother calls her kittens. Body language How a cat shows mood and intent through its tail, ears, eyes, whiskers, posture and fur. Kitten A cat in its first months of life, from birth until about six months to a year old, a time of rapid growth, learning and vaccinations.

Related guides

Why cats knead Why cats push their paws in and out on soft surfaces, what it tells you, how to handle sharp claws and when unusual kneading is worth a mention to a vet. Why cats purr Why cats purr, how the sound is made, the different kinds of purr, what it can mean besides contentment, and when a purring cat still needs a vet.