You know the sound before you’re properly awake. That flat, rhythmic hacking from somewhere on the landing, four or five goes at it, then quiet. You find the thing on the carpet on your way to the kettle and you don’t really think about it, because everyone knows cats do this.
That last bit is the problem. Hairballs occupy a strange spot in cat ownership: they’re gross enough that nobody wants to examine them closely, and normalised enough that almost nobody mentions them to a vet. There’s an entire aisle built on that assumption — pastes, treats, “hairball control” kibble — all of it quietly reinforcing the idea that this is a grooming by-product with a grooming-shaped fix.
Sometimes it is. But a cat bringing up hair is a cat vomiting, and vomiting is a symptom. The interesting question isn’t whether hairballs are normal. It’s how many is too many, and the number is lower than most owners assume.
The short version
- Cornell’s feline vets put one hairball every week or two in the not-unusual bracket. That’s the anchor to judge yours against.
- More often than that is worth investigating, not managing with paste.
- Two questions matter: is too much hair going in, or is the gut not moving it along?
- Over-grooming is the commonest reason for the first — and it’s usually a skin or pain problem, not a personality quirk.
- Repeated retching that brings nothing up, especially with lethargy or a day off food, is a same-day vet call. That can be an obstruction.
What’s in this guide
What normal actually looks like
There isn’t a clean scientific threshold here, which is partly why the topic drifts. But there is a workable one from people who see a lot of cats.
Read that as a ceiling rather than a target. Plenty of cats go months without producing one. If yours is at two a week, or one most days, you are outside the range where “cats just do this” is a satisfying answer.
Worth noticing too: hairballs are seasonal for a lot of cats. Spring and autumn coat changes produce a run of them, then it settles. A fortnight of extra hairballs in April is different from a pattern that has been building since Christmas. Direction of travel matters more than any single week.
“Hairball” is doing a lot of work
Before counting anything, be sure of what you’re actually seeing. Three quite different events get filed under the same word, and they point in different directions.
Vomiting
Active. Abdominal heaving, a few seconds of build-up, then something comes up — hair, food, bile, fluid. This is the one people mean.
Regurgitation
Passive and sudden. Food arrives back with no warning and no heaving, often tube-shaped and undigested. Different mechanism, different causes.
Coughing
Crouched low, neck and head stretched forward, repeated dry hacking — and nothing comes up. Owners very often log this as a hairball.
That third one is the one to be careful about. A cat crouched with its neck extended, hacking repeatedly and producing nothing, may well be coughing rather than trying to bring up hair — and in cats, coughing is a respiratory sign. Asthma affects somewhere between 1 and 5% of cats, and Cornell lists coughing or hacking among its signs, alongside wheezing, rapid or open-mouthed breathing.[2]
If your cat “does hairballs” but a hairball rarely appears afterwards, film it. Thirty seconds of phone video will settle in an instant what a paragraph of description can’t, and it’s the single most useful thing you can walk into an appointment holding.
Too much hair going in
Assuming it really is hair coming up, more hairballs means one of two things. Start with the simpler one: the cat is swallowing more hair than she used to.
Some of that is innocent. Long coat, moulting season, a second cat who grooms her, a change from indoor to outdoor life. But the version that matters is over-grooming, and here’s where the standard framing goes wrong. Over-grooming gets described as a stress behaviour, a nervous habit, the feline equivalent of nail-biting.
The clinical picture is less romantic. International Cat Care puts it plainly: the majority of over-grooming cases are initially caused by a skin problem or a pain problem, though most cases end up with a stress component layered on top.[3] Flea allergic dermatitis is the classic. Pain conditions matter too — a cat with lower urinary tract disease will often groom the belly, inner thighs and around the genitals, because that’s where the discomfort is.
So the sequence is backwards in most people’s heads. It’s not “she’s anxious, therefore she licks.” It’s usually “something itches or hurts, therefore she licks, and then licking becomes a habit that outlives the original problem.”
Part the fur on her lower back, right in front of the tail, and look at the skin. Then the belly and the insides of the back legs. You’re looking for thin or broken-off hair, stubble rather than bald patches, black flea dirt, scabs, or redness. Cats often over-groom out of sight, so the coat is more reliable evidence than anything you’ll witness.
The gut not moving it along
The second possibility is the one the hairball aisle can’t help with. A healthy cat swallows a lot of hair and passes nearly all of it in the litter tray. Hair reappearing at the top end is, to some extent, evidence that something is off with the journey.
This is where the “cats just vomit” assumption has taken a real beating in veterinary circles. A frequently cited study of 100 cats investigated for chronic small bowel disease — cats with signs like vomiting, weight loss and diarrhoea — found 49 with chronic enteritis and 50 with neoplasia, 46 of those being lymphoma. The authors took vomiting more than twice a month as abnormal and worth pursuing.[4]
Those 100 cats were selected because their vets already suspected small bowel disease and took them to biopsy. That is not a random sample of cats who occasionally bring up a hairball, and it absolutely does not mean half of all vomiting cats have lymphoma. What it does show is that when chronic vomiting in cats is properly investigated rather than shrugged off, it very often turns out to be a real disease with a name.
Which is the honest takeaway. Frequent hairballs aren’t a diagnosis of anything on their own. They’re a reason to look, at an age and in a species where looking early changes outcomes.
The other things worth flagging to your vet alongside frequent hairballs: gradual weight loss, a coat that’s lost its shine, appetite that’s climbed or dropped, softer stools, and drinking more. Cats are relentlessly good at hiding illness, which is why the small stuff carries so much weight. We’ve written about that pattern in a different context — a cat who goes to the water bowl but doesn’t drink is doing the same thing: showing you one small odd habit instead of an obvious symptom.
The version that’s an emergency
Cornell is direct about this: if your cat is lethargic and off food for more than a day or so, or has had repeated episodes of unproductive retching, contact your vet without delay.[1]
The reason is that a hairball doesn’t always come back up. It can pass out of the stomach into the intestine and lodge there, and an intestinal obstruction is life-threatening. The cat keeps trying, nothing arrives, and the trying itself is the sign.
Go the same day for: repeated retching with no result, no food for 24 hours, hiding or collapse, a swollen or painful belly, straining in the litter tray with nothing produced, or laboured breathing.
What helps, and what’s just sold
Once anything medical is ruled out or treated, there is genuinely useful stuff to do. It’s just less exciting than the packaging suggests.
- Brush her, properly and often. This is the intervention with the clearest logic behind it: hair on the brush is hair not in the stomach. Daily for a long-haired cat, a few times a week for a shorthair, and more during a moult. A five-minute habit beats a monthly wrestling match — and if she hates being brushed, start with thirty seconds in the spot she likes being scratched.
- Deal with fleas properly, all year. Not just when you see one. Flea allergic dermatitis is a leading cause of over-grooming, and a single bite can keep a sensitised cat licking for weeks.
- Get her weighed. Every few months, on the same scales. Weight loss in cats is the earliest signal of most chronic disease and is nearly impossible to see under fur. This costs nothing at most vet practices.
- Count, for a month. A note on your phone each time. “About once a fortnight” and “eleven times last month” produce entirely different appointments, and almost everyone underestimates.
- Feed wet food, or add water to it. Better hydration helps gut transit generally, and it’s a change with broad benefits regardless of hairballs.
On the products: hairball pastes are mostly petroleum-based lubricant laxatives, and “hairball control” foods are generally higher-fibre formulations. They may reduce the number of hairballs a healthy cat brings up. What they don’t do is address either underlying cause — a cat swallowing hair because her skin itches, or a gut that isn’t working properly. Used as a treatment they’re fine to try. Used as a way of not asking the question, they’re the most expensive part of this whole article.
The pattern is worth naming, because it repeats across pet care: a normal-sounding label, a product aisle built on it, and a symptom that quietly stops getting investigated.
Common questions
How often are hairballs normal in cats?
Roughly once every week or two is described by Cornell’s feline vets as not uncommon and nothing to worry about. Many cats produce far fewer. If your cat is bringing one up several times a week, or most days, that’s worth investigating rather than treating with hairball paste.
Are hairballs actually dangerous?
Usually not in themselves, but they can be. If a hairball passes from the stomach into the intestine instead of coming back up, it can cause a blockage, which is life-threatening. Repeated retching that produces nothing, especially alongside lethargy or refusing food, needs a vet the same day.
My cat hacks but nothing comes up. Is that still a hairball?
Often not. A cat crouched low with its neck extended, hacking repeatedly with no result, may be coughing rather than retching — and coughing in cats points at the airways, including asthma. Filming an episode is the fastest way to let your vet tell the difference.
Do hairball remedies and hairball-control food work?
They may reduce how many hairballs a healthy cat produces — the pastes are lubricant laxatives, the foods are usually higher in fibre. Neither treats over-grooming or gut disease, so they’re reasonable to use once a vet has ruled those out, and a poor reason to delay the appointment if the frequency has changed.
Why has my cat suddenly started getting hairballs?
A new pattern usually means one of three things: a seasonal moult, more hair being swallowed because she’s over-grooming, or a change in how well her gut is moving things along. The first settles within a few weeks. The other two don’t, and both are worth a look — over-grooming is most often driven by a skin or pain problem rather than stress alone.
The bottom line
Hairballs aren’t a disease, and an occasional one is genuinely part of owning a cat. But “cats do this” is a description, not an explanation, and it’s the phrase that keeps chronic vomiting out of consulting rooms.
Pick a number and hold yourself to it. One every week or two, no weight loss, coat in good condition, eating normally — carry on, brush her more. Beyond that, stop buying paste and book the appointment, ideally with a month of counted dates and a video on your phone.
Sources & references
- Cornell University College of Veterinary Medicine, Feline Health Center. A Hairy Dilemma. vet.cornell.edu
- Cornell University College of Veterinary Medicine, Feline Health Center. Feline Asthma: What You Need To Know. vet.cornell.edu
- International Cat Care. Over-grooming in cats. icatcare.org
- Norsworthy, G. D. et al. Diagnosis of chronic small bowel disease in cats: 100 cases (2008–2012). JAVMA 243(10). Summarised in Today’s Veterinary Practice journal club. todaysveterinarypractice.com
General information, not veterinary advice. If your cat’s hairball pattern has changed, or anything else has changed alongside it, speak to your vet rather than waiting it out. More cat health writing in our cat care section.
