Your Cat's Purr Can Mean the Opposite of What You Think — Here's When to Take It Seriously
Cat purring while being petted
Purring is one of the most recognizable things cats do. It is universally understood as a signal of contentment — a cat that purrs is a cat that is happy. This interpretation is so embedded in how people understand cats that it shapes nearly every other assumption owners make about their cat's emotional state.
It may also be leading people to miss something important.
What Dr. Siracusa found at AVMA 2025
At the American Veterinary Medical Association Convention in July 2025, Dr. Carlo Siracusa — a professor of clinical animal behavior and welfare at the University of Pennsylvania School of Veterinary Medicine — presented research that directly challenges the simple purring-equals-contentment model.
In a clinical study, Dr. Siracusa and colleagues observed increased purring in cats with chronic inflammatory disease (CID) — a category of conditions that causes persistent pain and discomfort. These cats purred more than healthy control cats. They also showed increased affection-seeking behavior: approaching their owners more, soliciting contact, vocalizing.
"They're just trying to express their emotions: I'm not feeling well. I'm relying on you."
— Dr. Carlo Siracusa, UPenn School of Veterinary Medicine · AVMA Convention 2025
The counterintuitive finding
A cat that suddenly becomes more affectionate, more vocal, or begins purring more than usual may not be signaling happiness. It may be asking for help in the only way available to it.
The biology of why cats purr when in pain
Purring is produced by the rapid movement of muscles in the larynx, creating a continuous sound during both inhalation and exhalation. The frequency range of a domestic cat's purr — typically 25 to 150 Hz — has been associated in some research with healing effects on bone density and tissue repair, which may be part of why cats purr during periods of stress or injury as a self-soothing mechanism.
But the communicative dimension of pain purring appears to be social: the cat is directing behavior toward its owner. It is soliciting care it cannot describe and cannot obtain for itself. In cats with chronic pain, this manifests as what owners frequently describe as their cat "becoming cuddlier with age" — an observation that in some cases reflects increased pain, not increased affection.
What to watch for
If your cat's purring behavior changes — either increasing significantly or changing in quality — it is worth paying attention, especially alongside other signals: changes in appetite, grooming patterns, litter box use, mobility, or how the cat responds to being touched in particular areas. A sudden increase in purring in an older cat is a reason to mention it at the next vet visit, not a reason to feel reassured.
The broader takeaway from Dr. Siracusa's research is that behavioral changes in cats — including seemingly positive ones like increased affection — should be interpreted in context rather than at face value. Cats are limited in how they can communicate pain. Paying close attention to changes rather than relying on the presence or absence of purring as a health proxy is a meaningful upgrade in how to care for them.
