Cats do purr when they are stressed, although it is less common than when they purr out of happiness. Stress purring is a self-soothing behavior that helps cats calm down and cope with anxiety or discomfort. This kind of purring can have a higher pitch and may accompany other signs of stress such as panting, showing teeth, or a tense body posture. Purring in stressful situations may also help cats relieve pain and promote healing through the vibrations generated by the purr. So, purring is not exclusively a sign of contentment but can also indicate stress or pain in cats depending on the context and other body language cues.
