What's the secret behind purring — do cats really purr when they're in pain too?

Quick answer

The contented purring your cat does in your lap is indeed a sign of happiness and comfort. But cats also purr at a frequency that self-soothes and can help heal bones and tissue when they're in severe pain or extreme fear. If your cat has no appetite, is curled up in one spot, and keeps purring, that could be a warning sign of pain — compare it against their usual behavior to check.