# Why do Cat's Purr **URL:** \ **Category:** Factual Questions\ **Created:** [March 1, 2003, 6:50am UTC](https://boards.straightdope.com/t/why-do-cats-purr/158359 "2003-03-01T06:50:31Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![jsb5048](https://avatars.discourse-cdn.com/v4/letter/j/a6a055/32.png) [@jsb5048](https://boards.straightdope.com/u/jsb5048)\ **Post date:** [March 1, 2003, 6:50am UTC](https://boards.straightdope.com/t/why-do-cats-purr/158359/1 "2003-03-01T06:50:31Z")
I was trying to get some sleep tonight when my roommates cat decided to climb iin bed with me and lay down right next to my face. Then I realize the cat was purring like crazy. I couldn’t help but think what makes them do that. And the rythm of the purring was not at the same pace of his breathing. Then it stopped. Iassumed he had fallen asleep… soemwhat mocking me. What’s with this puring thing the felines do? ---
**Author:** ![Derleth](https://avatars.discourse-cdn.com/v4/letter/d/b9e5f3/32.png) [@Derleth](https://boards.straightdope.com/u/Derleth)\ **Post date:** [March 1, 2003, 10:35am UTC](https://boards.straightdope.com/t/why-do-cats-purr/158359/2 "2003-03-01T10:35:14Z")
Cats purr whenever they are experiencing a strong emotion. In your roomie’s feline’s case, that emotion was probably contentment (Nothing makes a cat content faster than having a personal heater in the form of some giant ape’s head. :D), but a feline in extreme pain will also purr. I once read something somewhere that the subsonic vibrations created by purring will help bone knit, but I don’t know if I believe it. ---
**Author:** ![Alessan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alessan/32/465_2.png) [@Alessan](https://boards.straightdope.com/u/Alessan)\ **Post date:** [March 1, 2003, 11:55am UTC](https://boards.straightdope.com/t/why-do-cats-purr/158359/3 "2003-03-01T11:55:33Z")
It’s the other way around, Derleth - cats purr when they want to receive affection. A cat in extreme pain purrs because it needs someone to treat it. ---
**Author:** ![Sock\_Munkey](https://avatars.discourse-cdn.com/v4/letter/s/aeb1de/32.png) [@Sock\_Munkey](https://boards.straightdope.com/u/Sock_Munkey)\ **Post date:** [March 1, 2003, 12:13pm UTC](https://boards.straightdope.com/t/why-do-cats-purr/158359/4 "2003-03-01T12:13:15Z")
Cats can purr on the inhale and exhale, that’s why it’s a steady sound. ---
**Author:** ![Zoe](https://avatars.discourse-cdn.com/v4/letter/z/a4c791/32.png) [@Zoe](https://boards.straightdope.com/u/Zoe)\ **Post date:** [March 1, 2003, 12:37pm UTC](https://boards.straightdope.com/t/why-do-cats-purr/158359/5 "2003-03-01T12:37:47Z")
I heard recently that scientists don’t know _how_ cats purr. Is that true? ---
**Author:** ![Derleth](https://avatars.discourse-cdn.com/v4/letter/d/b9e5f3/32.png) [@Derleth](https://boards.straightdope.com/u/Derleth)\ **Post date:** [March 1, 2003, 12:49pm UTC](https://boards.straightdope.com/t/why-do-cats-purr/158359/6 "2003-03-01T12:49:12Z")
**Zoe** : We know. They have a seperate set of vocal cords. ---
**Author:** ![Will\_Repair](https://avatars.discourse-cdn.com/v4/letter/w/a698b9/32.png) [@Will\_Repair](https://boards.straightdope.com/u/Will_Repair)\ **Post date:** [March 1, 2003, 3:01pm UTC](https://boards.straightdope.com/t/why-do-cats-purr/158359/7 "2003-03-01T15:01:25Z")
New research indicates that cats may purr as a healing process. [http://www.animalvoice.com/catpurrP.htm](http://www.animalvoice.com/catpurrP.htm) [http://www.theage.com.au/news/2001/03/19/FFX0OF1MFKC.html](http://www.theage.com.au/news/2001/03/19/FFX0OF1MFKC.html) By the way, while looking into the Japan Snow Monkeys question I found an article of research about the sound frequency of kittens being one quarter the frequency of the mother cat. ---
**Author:** ![Mothchunks](https://avatars.discourse-cdn.com/v4/letter/m/a587f6/32.png) [@Mothchunks](https://boards.straightdope.com/u/Mothchunks)\ **Post date:** [March 1, 2003, 3:19pm UTC](https://boards.straightdope.com/t/why-do-cats-purr/158359/8 "2003-03-01T15:19:47Z")
“A purr can be felt by the kittens and keeps them calm without giving away their position to a predator.”~NOVA I have many cats. To me, a purr is the same as an Om. There is a reason that Egyptians considered cats to be sacred animals, and that they make such good familiars. ---
**Author:** ![Eve](https://avatars.discourse-cdn.com/v4/letter/e/9e8a1a/32.png) [@Eve](https://boards.straightdope.com/u/Eve)\ **Post date:** [March 1, 2003, 5:01pm UTC](https://boards.straightdope.com/t/why-do-cats-purr/158359/9 "2003-03-01T17:01:30Z")
I have heard this “cats purr when they’re in pain” gag for years, and I just don’t buy it. I’ve been around cats all my life and have seen cats sick, scared, in pain (no, not because of me!) and I have _never_ heard them purr under these circumstances. When they are happy, contented–that’s it. ---
**Author:** ![InternetLegend](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/internetlegend/32/13154_2.png) [@InternetLegend](https://boards.straightdope.com/u/InternetLegend)\ **Post date:** [March 1, 2003, 5:08pm UTC](https://boards.straightdope.com/t/why-do-cats-purr/158359/10 "2003-03-01T17:08:22Z")
> [@](#): > > \*Originally posted by Eve \* > \*\*I have heard this “cats purr when they’re in pain” gag for years, and I just don’t buy it. I’ve been around cats all my life and have seen cats sick, scared, in pain (no, not because of me!) and I have _never_ heard them purr under these circumstances. \*\* You should come meet my cat. My 18-year-old tabby invariably purrs when he’s distressed. I believe it may have helped save his life when he had a very serious illness five years ago - there’s something very compelling about a cat who purrs at you while you flush a chest tube, and the emergency vet stayed up all night with him doing just that, despite the cat’s advanced age and slim chances of survival. He purrs when getting injections, too, and our regular vet sometimes has trouble hearing his breath sounds and heartbeat clearly through the purring. I must admit, this is the only cat we’ve ever had who will always purr when he’s in pain, but I have occasionally seen (heard) it from some of our other cats, too.