Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

Healthy Pets

Font Size

Why Do Cats Purr?

Purring is the most common sound cats make. Yet we know less about it than meowing, chirping, chattering, hissing, and growling.

Yes, cats purr when they're content. When yours is curled up in the sun, you may hear a gentle rumble as he breathes in and out. Touch him, and you feel a little quiver. It's almost as if he's sending out waves of calm.

Recommended Related to Pets

Cold Weather Pet Care Tips’s cold outside! The following guidelines will help you protect your companion animals when the mercury dips. Keep your cat inside. Outdoors, felines can freeze, become lost or be stolen, injured or killed. Cats who are allowed to stray are exposed to infectious diseases, including rabies, from other cats, dogs and wildlife. During the winter, outdoor cats sometimes sleep under the hoods of cars. When the motor is started, the cat can be injured or killed by the fan belt. If there...

Read the Cold Weather Pet Care Tips article > >

But you shouldn't assume that sound means your cat is in a good mood. Or that it's the only time you'll hear it. Cats purr to communicate other emotions and needs, too.

What if you pick your cat up and hold him? Does he purr because he likes it -- or because he's nervous?

Although you'll never know exactly what yours is saying when he purrs, research from animal experts, along with considering the situation, lets you make an informed guess.

She's Happy

Your cat looks relaxed: Perhaps she's on her back, eyes half-closed, tail mostly still. If she's purring, it's safe to assume she's in her happy place.

That noise is a big smile.

He's Hungry or Wants Something

Some cats purr when it's mealtime. British researchers studied the sounds that house cats make when they're hungry and when food isn't on their minds. The purrs don't sound the same.

When cats purr for food, they combine their normal purr with an unpleasant cry or mew, a bit like a human baby's cry. Experts believe that we're more likely to respond to this sound. They've found that people can tell the difference between the purrs, even if they aren't cat owners.

Kitten-Mother Connection

Kittens can purr when they're only a few days old. It's probably a way to let their mothers know where they are or that they're OK.

Purring also helps a kitten bond with its mother. Mama cats use it like a lullaby.

Relief and Healing

Even though purring takes energy, many cats purr when they get hurt or are in pain. So what makes the effort worth it?

It might simply be a way for a cat to soothe itself, like a child sucks their thumb to feel better.

But some research suggests that purring actually helps cats get better faster. The low frequency of purrs causes a series of related vibrations within their body that can:

  • Heal bones and wounds
  • Build muscle and repair tendons
  • Ease breathing
  • Lessen pain and swelling

This might explain why cats are able to survive falls from high places and tend to have fewer complications after surgeries than dogs.

WebMD Medical Reference

Reviewed by Amy Flowers, DVM on February 18, 2015

Today on WebMD

Puppy digging hole
Are you putting your pet at risk?
Cat looking at fish
Things we can learn from our pets.
dog and kitten
27 ways pets help your health.
Get the facts about prevention.
Woman holding puppy
Sad dog and guacamole
Siamese cat eating from bowl
cat on couch
Cat People vs Dog People Slideshow
Kitten playing
Orange cat nuzzling woman
German shephard reading a book