Cats are experts at hiding discomfort. Unlike dogs, many cats may continue acting relatively normal even when something is wrong. That is why small changes in eating, drinking, grooming, litter box habits, energy, or behavior can be important clues for cat owners.
So, what are signs your cat is unhealthy?
Some symptoms are easy to notice, such as vomiting, diarrhea, or a visible injury. Others are much more subtle. Your cat may spend more time hiding, stop jumping onto furniture, sleep more than usual, or simply seem "different." These changes should not automatically be ignored as normal aging or a change in personality.
Recognizing possible signs of illness early can help you get veterinary advice before a minor problem becomes more serious.
This guide covers 10 common warning signs that your cat may be sick, what they could mean, and when you should contact a veterinarian.
Important: This article is for general educational purposes and does not replace veterinary diagnosis or treatment. If your cat has severe, sudden, or worsening symptoms, contact a veterinarian or emergency veterinary service promptly.
1. Your Cat Stops Eating or Eats Much Less
A sudden change in appetite is one of the most important signs to watch.
Cats can occasionally skip a meal because of stress, environmental changes, or a temporary upset stomach. However, a noticeable or persistent decrease in food intake can indicate that something is wrong.
Possible causes include:
-
Dental or mouth pain
-
Gastrointestinal problems
-
Infection
-
Stress or anxiety
-
Kidney or liver problems
-
Pain elsewhere in the body
-
Medication side effects
-
Other underlying illnesses
Cats that stop eating are particularly concerning because prolonged lack of food can lead to serious complications. If your cat suddenly refuses food, especially if they are also vomiting, weak, hiding, or acting unusually, contact your veterinarian.
It is also useful to monitor how much your cat normally eats. Keeping a record of meals can make it easier to recognize changes.
With FurMyLife, you can keep important information about your pet organized in one place, including health records, medications, conditions, allergies, and veterinary information. Explore FurMyLife
2. Drinking Much More or Much Less Than Usual
Changes in water consumption can be easy to overlook, particularly if your cat drinks from several locations around the home.
If your cat suddenly begins drinking significantly more water, it may be worth discussing with your veterinarian. Increased thirst can occur with several health conditions, including kidney disease, diabetes, and other disorders.
Drinking less can also be concerning, particularly when accompanied by vomiting, diarrhea, weakness, or reduced appetite.
The key is to know your cat's normal routine.
If you notice that the water bowl is suddenly empty much more often, your cat is visiting the water bowl repeatedly, or your cat barely seems to drink, pay attention to the pattern.
You should also consider environmental factors. Hot weather, a change from dry food to wet food, or increased activity can affect water intake.
When a change is sudden or persistent, veterinary advice is the safest approach.
3. Changes in Litter Box Habits
Your cat's litter box can provide valuable clues about their health.
Changes in how often your cat urinates or defecates, the amount produced, or how your cat behaves inside the litter box may indicate a problem.
Watch for signs such as:
-
Frequent trips to the litter box
-
Straining to urinate
-
Crying or vocalizing while using the litter box
-
Urinating outside the litter box
-
Blood in urine or stool
-
Diarrhea
-
Constipation
-
Very small amounts of urine
-
A noticeable increase in urine production
Urinary problems deserve particular attention. Difficulty urinating can become an emergency, especially in male cats.
If your cat repeatedly tries to urinate but produces little or no urine, do not wait to see whether it improves. Seek veterinary care immediately.
Keeping track of your cat's health history can also help your veterinarian identify changes over time. FurMyLife's health records are designed to keep information such as veterinary visits, medications, conditions, allergies, and vaccines organized in a pet profile.
4. Vomiting or Diarrhea That Keeps Happening
Occasional vomiting can happen in cats, including after eating too quickly or bringing up a hairball. However, repeated vomiting or persistent diarrhea should not be dismissed as normal.
These symptoms can have many possible causes, ranging from dietary issues to infections and other medical conditions.
Pay attention to:
-
How frequently your cat vomits
-
Whether there is blood
-
Whether your cat can keep water down
-
Changes in appetite
-
Diarrhea frequency
-
Changes in stool color or appearance
-
Weakness or unusual sleepiness
-
Signs of pain
A cat experiencing repeated vomiting or diarrhea can become dehydrated.
If your cat is vomiting repeatedly, has severe diarrhea, appears weak, has blood in vomit or stool, or cannot keep fluids down, contact a veterinarian promptly.
Do not give human medications unless a veterinarian specifically tells you to do so. Some medications that are safe for people can be dangerous or toxic to cats.
5. Hiding More Than Normal
Cats naturally enjoy quiet, private places. Hiding by itself does not necessarily mean your cat is sick.
The concern is a change from normal behavior.
If your social cat suddenly spends most of the day under the bed, avoids family members, or stops coming out for meals, something may be wrong.
Cats may hide because they are:
-
Experiencing pain
-
Feeling stressed
-
Frightened
-
Sick or weak
-
Adjusting to an environmental change
A cat that is hiding while also refusing food, vomiting, breathing abnormally, or showing other symptoms deserves particular attention.
You know your cat's personality better than anyone. If their behavior suddenly seems unusual, take the change seriously.
6. Sudden Changes in Grooming
Healthy cats generally spend a significant amount of time grooming themselves.
That makes grooming behavior another useful health indicator.
A sick or painful cat may groom less frequently. Their coat may become greasy, tangled, or unkempt.
On the other hand, excessive grooming can also indicate a problem. Your cat may repeatedly lick one area because of pain, skin irritation, parasites, allergies, or another source of discomfort.
Look for:
-
A dull or messy coat
-
Matted fur
-
Bald patches
-
Red or irritated skin
-
Excessive licking
-
Constant scratching
-
A sudden decrease in grooming
Regularly checking your cat's coat and skin can help you notice changes early.
If you find wounds, swelling, persistent irritation, parasites, or significant hair loss, speak with your veterinarian.
7. Changes in Energy or Activity
Has your normally playful cat stopped chasing toys?
Is your cat sleeping much more than usual?
Are they no longer jumping onto their favorite chair?
A noticeable reduction in activity can be a warning sign.
Cats may become less active because they are experiencing pain, weakness, illness, stress, or age-related changes.
However, don't assume every reduction in activity is simply because your cat is getting older.
A cat that suddenly becomes reluctant to jump, climb stairs, play, or move around may be experiencing discomfort.
Try to compare your cat's current behavior with their normal routine.
For example, if your cat usually greets you at the door but suddenly stays in bed, that change is worth noticing.
Keeping your pet's weight, health information, medications, and veterinary history organized can make these changes easier to discuss with a veterinarian. FurMyLife provides a digital pet profile where important health information can be stored together.
8. Unusual Breathing or Coughing
Breathing problems should always be taken seriously.
Signs that your cat may be having respiratory difficulty can include:
-
Rapid breathing
-
Labored breathing
-
Open-mouth breathing
-
Persistent coughing
-
Wheezing
-
Unusual breathing sounds
-
Excessive effort when breathing
-
Blue or pale-looking gums
Cats normally breathe quietly without obvious effort. If you notice that your cat is struggling to breathe, this is not something to monitor casually at home.
Open-mouth breathing or obvious difficulty breathing can be an emergency. Seek immediate veterinary care.
Avoid stressing or chasing your cat if they are having trouble breathing. Keep them calm and transport them safely to veterinary care.
9. Weight Loss or Weight Gain
Changes in body weight can develop gradually, making them difficult to notice.
Regularly monitoring your cat's weight can help you identify trends earlier.
Unexplained weight loss may occur with various health problems, while unexplained weight gain can sometimes be associated with overeating, reduced activity, or other conditions.
Look beyond the number on the scale.
You may notice:
-
Ribs becoming more visible
-
A thinner-looking face or body
-
A suddenly rounder abdomen
-
Reduced muscle around the back legs
-
Changes in appetite despite weight loss
-
Changes in activity
If your cat's weight changes without an obvious reason, speak with your veterinarian.
A digital health record can also make weight monitoring easier. FurMyLife allows pet parents to maintain pet information, including weight and health history, within their pet profile.
10. Changes in Behavior, Mood, or Vocalization
Sometimes the first sign that a cat is sick is simply that they are behaving differently.
Your cat may suddenly become:
-
More aggressive
-
More vocal
-
Less affectionate
-
Restless
-
Irritable
-
Fearful
-
Confused
-
Unusually quiet
A cat that normally enjoys being handled may suddenly avoid touch because something hurts.
Similarly, increased vocalization may occur when a cat is uncomfortable or distressed.
Behavior changes can also result from stress, changes in the household, environmental changes, or aging. That is why context matters.
Look for combinations of symptoms rather than relying on one behavior alone.
For example, a cat that is hiding, not eating, and vocalizing when touched is more concerning than a cat that simply chooses a new sleeping location.
Other Warning Signs Cat Owners Should Know
The 10 symptoms above are among the most useful changes to watch for, but they are not the only warning signs.
You should also pay attention to:
-
Swelling or unusual lumps
-
Eye discharge
-
Squinting or painful-looking eyes
-
Nasal discharge
-
Bad breath that suddenly becomes severe
-
Drooling
-
Difficulty chewing
-
Limping
-
Balance problems
-
Seizures
-
Sudden weakness
-
Pale gums
-
Blood in urine, stool, or vomit
-
Signs of significant pain
The more symptoms your cat develops, the more important it becomes to seek professional veterinary advice.
When Should You Take Your Cat to the Vet?
Not every unusual symptom means your cat needs an emergency visit. However, some situations require immediate attention.
Seek urgent veterinary care if your cat has:
-
Difficulty breathing
-
Open-mouth breathing
-
Collapse or severe weakness
-
Seizures
-
Severe injury
-
Repeated attempts to urinate without producing urine
-
Severe or uncontrolled bleeding
-
Sudden inability to walk normally
-
Severe pain
-
Suspected poisoning
-
A sudden major change in consciousness or responsiveness
For less urgent changes, such as mild appetite changes or gradually developing weight loss, contact your regular veterinarian and explain what you have observed.
When speaking with your veterinarian, provide as much information as possible. Tell them when the symptoms started, how often they occur, whether your cat is eating and drinking normally, and whether their litter box habits have changed.
Keep Your Cat's Health Information Organized
One of the biggest challenges for pet owners is remembering everything about their pet's health history.
When was the last vaccine?
What medication did your cat take?
What was their previous weight?
When did the symptoms begin?
Which veterinarian treated them?
Keeping this information organized can make veterinary visits easier.
FurMyLife is designed to give pet parents a central place for important pet information. You can create a digital pet profile and organize health records, vaccines, medications, allergies, conditions, and veterinary visits.
The platform also includes PawBot AI, which can provide personalized pet-care guidance using information from your pet's profile. It is designed to be more personalized than generic pet advice because it can consider information such as your pet's breed, weight, age, vaccine history, and health records.
However, AI should not replace a veterinarian. Serious or worsening symptoms should always be evaluated by a qualified veterinary professional.
Create your free FurMyLife pet profile
How PawBot Can Help You Monitor Your Cat
Pet owners often search online when they notice something unusual.
The problem is that general search results may provide information without knowing anything about your specific cat.
FurMyLife's PawBot is designed around your pet's profile. Depending on the information you have provided, it can use details such as breed, weight, age, vaccines, and health history when providing general care guidance.
For example, you might have questions about your cat's weight, vaccination schedule, or general care.
The goal is not to diagnose your cat but to help you stay informed and organized.
PawBot also includes a clear reminder that serious symptoms should be confirmed with a veterinarian.
That distinction is important: AI can help you organize information and understand general possibilities, but it cannot replace a physical examination or professional veterinary diagnosis.
Prevention Starts With Knowing What's Normal
One of the best ways to recognize illness in a cat is to understand your cat's normal behavior.
Know:
-
How much your cat normally eats
-
How much they usually drink
-
How often they use the litter box
-
Their normal weight
-
Their typical energy level
-
Their usual grooming habits
-
Their normal personality
-
Their favorite activities
-
How they normally interact with you
When you know your cat's baseline, changes become easier to recognize.
Regular veterinary checkups are also an important part of preventive care. Cats can hide signs of illness, so professional examinations can identify problems that may not be obvious at home.
Final Thoughts
So, what are signs your cat is unhealthy?
The answer is not always one dramatic symptom. Often, illness begins with a collection of small changes: eating less, drinking more, hiding, grooming differently, sleeping more, using the litter box differently, losing weight, or acting unlike themselves.
The most important thing is to pay attention to changes from your cat's normal behavior.
If something seems unusual, document what you are seeing and contact your veterinarian when appropriate. If your cat has severe symptoms, breathing difficulty, inability to urinate, collapse, severe pain, or another emergency sign, seek immediate veterinary care.
And don't wait until you need your cat's health history to start organizing it.
With FurMyLife, you can create a digital profile for your pet, keep health records organized, track important information, use PawBot for personalized general pet-care guidance, and keep essential details accessible when you need them.
Start FurMyLife for free — no credit card required
FAQs
1. What are the most common signs that a cat is sick?
Common signs include loss of appetite, changes in drinking or litter box habits, vomiting, diarrhea, hiding, changes in grooming, low energy, unusual breathing, weight changes, and sudden behavior changes.
2. How can I tell if my cat is unhealthy?
Watch for changes from your cat's normal routine. Eating less, drinking more or less, hiding frequently, losing weight, grooming differently, or becoming unusually quiet can indicate that something may be wrong.
3. When should I take my cat to the vet?
Contact your veterinarian if symptoms are persistent, worsening, or unusual for your cat. Difficulty breathing, collapse, seizures, severe pain, or inability to urinate require urgent veterinary attention.
4. Is it normal for a sick cat to hide?
Yes. Cats often hide when they are experiencing pain, illness, fear, or stress. If hiding is a sudden change in your cat's normal behavior, monitor for other symptoms and consider contacting your veterinarian.
5. Why has my cat suddenly stopped eating?
Loss of appetite can have many causes, including dental pain, illness, stress, digestive problems, or other medical conditions. A sudden or persistent loss of appetite should be discussed with a veterinarian.
6. Why is my cat drinking more water than usual?
Increased thirst can have several causes, including changes in diet or environment and certain health conditions. If your cat consistently drinks much more than usual, contact your veterinarian.
7. Are changes in litter box habits a sign of illness?
Yes. Straining, frequent trips to the litter box, urinating outside the box, blood in urine or stool, constipation, diarrhea, or producing very little urine can indicate a health problem.
8. Can FurMyLife help me monitor my cat's health?
Yes. FurMyLife lets you organize your cat's digital profile, health records, vaccines, medications, allergies, conditions, and veterinary information in one place.
9. Can PawBot AI diagnose my sick cat?
No. PawBot AI provides personalized general pet-care guidance based on information in your pet's profile, but it does not replace a veterinarian. Serious or worsening symptoms should always be evaluated by a qualified veterinary professional.
10. How can I keep track of my cat's health information?
You can use FurMyLife to keep important information such as weight, vaccinations, medications, allergies, health conditions, and veterinary visits organized in your pet's digital profile.
Your cat can't tell you when something is wrong. Knowing their normal behavior can help you notice when something changes.