Your cat is almost certainly better at hiding pain than you are at spotting it, and that isn’t a failure on your part. It’s biology. Cats evolved as both predators and prey, and in the wild, an animal that broadcasts weakness becomes a target. So cats conceal discomfort by instinct. The dramatic yowling when you’re five minutes late with dinner is theater. Real pain tends to arrive silently.
The scale of what gets missed is genuinely startling. Osteoarthritis, one of the most common sources of chronic pain in cats, shows up on X-rays in the large majority of senior cats, with some studies finding radiographic evidence in around 90 percent of cats over 12. Yet in one well-known study, only about 4 percent of those arthritic cats had arthritis noted by either their owner or their vet. A more recent analysis estimated the condition goes undetected in the vast majority of affected cats. We are not slightly missing feline pain. We are missing it almost entirely.
That’s the case for learning to read the quiet signals. Here are the behavioral changes worth watching for, ordered roughly from the ones you can spot from across the room to the ones that take a deliberate, close look, plus a tool that can catch what behavior alone can’t.
The one rule that matters most
Before the list, the single most useful principle: any change in behavior should be taken seriously. Cats have an uneasy relationship with change. They rarely alter their habits without a reason, so a shift, especially a sudden one, is itself the signal. The specific signs below are really just the most common ways that underlying rule shows up.
1. Reluctance to move, jump, or climb
Sometimes the signs are nearly physical. A general reluctance to move, a new limp, an odd or altered gait, or sudden trouble jumping up to a favorite perch all point to pain. The cat who used to land effortlessly on the counter and now hesitates, or takes the “stairs” of a chair first, is very often an arthritic cat, even if no one has used that word yet.
2. Hiding and social withdrawal
A cat who suddenly starts hiding should be assessed. Some seek out dark spots to avoid bright light; others retreat to avoid social interaction and, with it, any physical contact. Even cats who don’t fully disappear may pull back from the family. In a gregarious cat, this is obvious. In a more reserved one, even a small dip in sociability can be a big clue.
3. Over-grooming or under-grooming
Watch grooming in both directions. Persistent licking of one body part, especially an area the cat didn’t fuss over before, can flag pain there. The opposite matters too: a noticeable drop in grooming, leaving a once-tidy coat unkempt or matted, is a classic sign of a cat who doesn’t feel well enough to keep up appearances.
4. Agitation, aggression, or litter-box changes
When a cat shows behavior you’ve never seen before, pain is a leading suspect. A hurting cat may become agitated or even aggressive, particularly if touched or startled. Pain also drives some cats to eliminate outside the litter box, either because climbing in hurts or because they associate the box with a painful episode. A previously fastidious cat breaking that habit warrants a vet visit, not a scolding.
5. Vocalizing differently
More vocalizing, or vocalizing in an unusual way, crying, groaning, growling, or hissing, can signal pain. So can resisting touch that was previously welcome, especially objection to being touched in one specific spot. A cat who suddenly hates being picked up, or flinches when you stroke a particular area, is giving you a map.
6. Changes in sleep, energy, and appetite
A cat sleeping more, or in new places, can be telling you something, as can a drop in appetite or water intake. Watch for a cat who keeps their eyes closed or squinted more than usual, or who’s suddenly indifferent to toys that used to trigger instant play. Less energy and less interest are early, easy-to-rationalize clues, which is exactly why they get rationalized away.
7. Changes in facial expression
This is the sign most owners don’t know to look for, and it may be the most reliable of all. Cats in pain change their faces in measurable ways, and researchers have turned that into a validated tool: the Feline Grimace Scale (FGS). It scores five features, ear position, orbital tightening (a squinted, tense eye), muzzle tension, whisker position, and head position, each from 0 to 2.
A pained cat tends to flatten or rotate the ears outward, squint, tense the muzzle, and lower the head. The FGS is fast, validated for acute pain in both clinical and home settings, and available as a free app, and studies show even short training improves how accurately people apply it. It won’t replace a vet, but it gives you something behavior alone doesn’t: a structured, repeatable read on your cat’s face. (One caveat from the research: the FGS is validated for acute pain, not chronic conditions, so it’s a snapshot, not a monitor for long-term arthritis.)
When to call the vet
Some signs are worth a same-day or urgent call rather than watchful waiting:
- Not eating for more than 24 hours (cats can develop serious liver problems quickly when they stop eating)
- Straining in the litter box or producing little or no urine (a possible emergency, especially in male cats)
- Crying out, hissing, or biting when touched in a specific area
- Hiding combined with lethargy or hunched posture
- A limp, stiffness, or trouble jumping that doesn’t resolve
For anything sudden or severe, don’t wait it out. For subtler, ongoing changes, the slowing-down senior is the one to flag, because “just getting old” is exactly how feline osteoarthritis hides in plain sight.
Your cat can’t tell you in words that they hurt. But between these seven behavioral signs and a tool like the Grimace Scale, they’re telling you all the same. The job is learning to listen, and then trusting what you notice enough to make the call.
This article is informational and isn’t a substitute for veterinary care. If you think your cat may be in pain, contact your veterinarian.
References
- Lascelles BDX et al., “Cross-sectional study of the prevalence of radiographic degenerative joint disease in domesticated cats”, The Veterinary Journal
- Evangelista MC et al., “Facial expressions of pain in cats: the development and validation of a Feline Grimace Scale”, Scientific Reports
- 2022 AAHA Pain Management Guidelines for Dogs and Cats, “full guidelines (PDF)”
- Feline Grimace Scale, “official tool and app”
