Symptom guide

Why Is My Cat Vomiting? Hairballs, Causes and When to Worry

Is your cat throwing up? When hairballs are normal, the common causes of vomiting in cats, and the signs that mean a vet visit.

Updated October 2026 · 7 min read · By the Hushku editorial team · 2 sources

Monitor at home; call your vet if it worsens. Vet if more than once a week or other signs

Short answer

Bringing up a hairball every week or two can be normal, but cats shouldn't vomit regularly. Cornell's Feline Health Center advises a vet visit if your cat vomits more than once a week, or if vomiting comes with lethargy, weakness, eating less, blood, drinking or urinating more or less, or diarrhoea.

Key facts

A hairball every week or two can be normal; vomiting more than once a week isn't.
Lilies, string and human medicines are dangerous causes in cats.
Chronic vomiting in older cats is often from kidney disease, hyperthyroidism, IBD or intestinal cancer.
Never pull string from a cat's mouth or bottom.

This guide is general information, not a diagnosis. If your pet seems unwell, or you're worried, call your vet.

Overview

Many owners assume cats "just throw up", but frequent vomiting is not normal and is often a sign of an underlying problem. Older cats in particular vomit because of conditions such as kidney disease, an overactive thyroid, inflammatory bowel disease or intestinal cancer, which are easier to manage when found early.

Hairballs are tube-shaped clumps of hair mixed with fluid. Bringing one up every week or two is common, especially in long-haired cats, and is actually protective: a hairball that moves into the intestines can cause a blockage. More frequent hairballs, or vomiting food, foam or fluid, should be checked.

Vomiting or regurgitation? Vomiting involves heaving from the belly; regurgitation brings food up passively, often straight after eating. Fast eaters sometimes regurgitate undigested food; a puzzle feeder or smaller meals can help.

Go to a vet now if you see

Repeated vomiting in a short time, or vomiting and unable to keep water down
Blood in the vomit
Your cat may have chewed or touched lilies, or eaten string, medicine or a toxin
Lethargy, hiding, collapse or a painful belly
A male cat straining in the litter tray (possible urinary blockage)

Common causes

1. Hairballs
Usually mild
Common, especially in long-haired cats and cats that groom a lot. Brushing reduces them.
2. Eating too fast or a food change
Usually mild
Gulping food or switching diets suddenly can cause vomiting soon after meals.
3. Swallowed string, thread or objects
Serious
String, ribbon, hair ties and tinsel are dangerous: they can bunch up the intestines. Never pull string from a cat's mouth or bottom; see a vet.
4. Poisoning
Serious
Lilies (all parts, even pollen), human medicines, antifreeze, onions and some cleaning products. Lily exposure is an emergency.
5. Intestinal parasites
Needs a vet
Worms are a common cause in kittens and cats that hunt.
6. Inflammatory bowel disease or food intolerance
Needs a vet
Chronic vomiting, sometimes with weight loss or diarrhoea, in adult cats.
7. Kidney disease, hyperthyroidism and diabetes
Serious
Common in older cats, often with weight loss and drinking more.
8. Intestinal cancer
Serious
Lymphoma is one of the more common causes of chronic vomiting and weight loss in older cats.

What you can do at home

Brush your cat regularly, especially long-haired cats, to cut down on hairballs.
For a single vomit in a cat that is otherwise well, offer a small meal a few hours later and watch.
Fast eaters: try smaller, more frequent meals or a puzzle feeder.
Keep a note of how often your cat vomits and what comes up; photos help your vet.
Never give human medicines; many, including paracetamol, are toxic to cats.

When to see a vet

Any emergency sign: go now
Vomiting more than once a week, or hairballs more than every week or two
Vomiting with weight loss, eating less, drinking more or diarrhoea
A cat that hasn't eaten for 24 hours or more

Prevention

Brush regularly and ask your vet about hairball diets if needed
Keep lilies out of the home entirely
Put away string, ribbon, hair ties and tinsel
Keep up with parasite control
Senior cats: twice-yearly check-ups with blood tests

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Sources

We check guides against veterinary sources and update them when guidance changes. How we write and review.

Questions.

How often is it normal for a cat to vomit?

An occasional hairball every week or two can be normal. Vomiting more than once a week isn't, and is worth a vet check.

Why does my cat throw up after eating?

Often because it ate too fast, especially dry food. Smaller meals or a puzzle feeder can help. If it continues, see your vet to rule out other causes.

My cat vomited but is acting normal. Should I worry?

A single vomit in a cat that is otherwise eating and behaving normally is usually not urgent. Keep an eye on it and see a vet if it happens again soon or other signs appear.

Key facts

Overview

Go to a vet now if you see

Common causes

1. Hairballs

2. Eating too fast or a food change

3. Swallowed string, thread or objects

4. Poisoning

5. Intestinal parasites

6. Inflammatory bowel disease or food intolerance

7. Kidney disease, hyperthyroidism and diabetes

8. Intestinal cancer