Get

In Your Inbox

Catster is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Learn more.

Why Is My Cat Acting Weird? 5 Vet-Reviewed Reasons

Share

a woman holding a cat on her lap

Some cats display what many owners would consider odd or weird behavior regularly. Others settle into a routine and can be quite predictable. This predictability makes changes in behavior even more obvious. If your cat is showing sudden changes in its habits, it is a sign that something is up. It might be as simple as a change in your cat’s routine that has thrown them off. Or it could be a sign of something more serious, such as anxiety or even illness.

Below are the five of the more common causes of your cat acting weird or exhibiting weird behavior, as well as other signs to look for to help identify the likely cause.

divider 3 paws

The 5 Reasons For Your Cat Acting Weird

1. Depression

It might sound like a uniquely human problem, but cats can get depressed, too. Whether your cat has lost a feline friend or even a close human companion, it can display symptoms of depression that include acting out of character.

Be patient with your depressed cat. Ensure they have food and water and give them space. Speak softly and try getting your cat’s attention using treats and toys to get them out of hiding. Contact a vet if signs last more than 1-2 days.

If you need to speak with a vet but can't get to one, head over to PangoVet. It's an online service where you can talk to a vet online and get the advice you need for your pet — all at an affordable price!

PangoVet_Mention-in-Content for PangoVet2 save money


2. Stress

Feline anxiety can be caused by any number of factors, but one of the most common is a change in routine. Cats are creatures of habit. They like to eat at a similar time every day, go outside at the same time, and they like to have the same people around them. If any of these routines change, it can lead to stress. If you can’t revert to your cat’s original routine, try and ease them into the changes gradually.

Some of the common causes of stress in cats include:
  • Moving house
  • Having work done to the house
  • A new pet
  • A new family member
  • Unexpected loud noises
  • A dirty litter tray
  • Change in diet
  • Being left home alone

3. Under Threat

In the wild, cats are both predators and prey. They spend a lot of their time ensuring that they aren’t being threatened by bigger animals looking to predate them. While they might not be under any real threat in your home, the natural instinct to be vigilant remains. If your cat sees, hears, or otherwise senses any disturbance or change that might appear to be a threat, it can lead to stress and subsequent behavioral changes.

Listen out for loud noises that have started in the neighborhood. Maybe a dog has moved in next door and your cat can hear it running around or barking at delivery drivers. The perceived threat could also come from within. If you’ve recently adopted a new cat, a dog, or even introduced a new human family member to the fold, your cat might view them as a threat and this could be causing the weird behavior.

cat hiding
Image Credit by: Mantikorra, Shutterstock

4. Sickness

Wild cats do very well at hiding illness and any sign of weakness that competitors might pounce on. Domestic cats have retained much of this behavior, as well. Odd behavior in your cat, therefore, could be linked to illness, and you should look for other signs.

Some common signs of illness include:
  • Change in eating habits – Monitor your cat’s eating habits so you can determine whether they are eating more or less. An increased or decreased appetite could be a sign of illness, and if the change continues, you should consult a vet.
  • Weight changes – A change in eating habits can obviously lead to your cat putting on more weight or losing it, but if your cat’s weight is changing and it can’t be explained by a change in diet or exercise, this is a sign that something is wrong and you should take them to be checked by a vet.
  • Change in litter habits – Similarly, a change in eating habits can lead to a change in litter habits, although any changes should be minimal. Changing your cat’s food is another possible culprit of litter habit changes. But gastrointestinal problems can be caused by a host of different illnesses, so keep an eye on increased or decreased urination and pooping, or any evidence of blood or straining.
  • Change in exercise and energy levels – You know how active your cat is. If your cat, who normally loves to chase a ball around for half an hour, suddenly has no interest in getting up, it can be a sign of anxiety or depression. It can also be a sign of illness. Even an increase in energy level could be a sign that something is wrong and might warrant further investigation.
  • Excessive fur shedding – Your cat’s coat can be one of the first areas to suffer if your cat gets ill. If the normally healthy, clean, luster of the coat has been lost and your cat is shedding, it might be that they have fleas or mites. Both of these can be irritating and both can lead to much more serious illnesses. Speak to a vet to get help with these issues.
  • Excessive grooming – Cats are clean animals and most spend a lot of time grooming and cleaning themselves. However excessive grooming might be an indication of something fairly simple like an irritable skin condition or allergic reaction. But it could be a sign of something bigger.
  • Vomiting – Some cats might occasionally bring back food that disagrees with them, and it isn’t that uncommon for cats to bring up furballs. It might be cause for concern, however, if your cat vomits more than once, and coughing up furballs can be a sign of overgrooming, nutritional problems, or other health concerns.

5. Lack of Stimulation

Cats need mental stimulation as well as physical exercise. If they are lacking either of these, it can cause them to get ill, but it can also lead to boredom. Ensure your cat gets a good amount of daily exercise. This may mean hosting regular play sessions if your cat is kept strictly indoors. Also provide toys, especially interactive toys, when you are out of the house.

They will keep your cat entertained and keep their minds busy, therefore helping to stave off boredom and depression. Interactive toys include treat toys, licky mats, and more.

divider 2 cats

Conclusion

Most owners get to know the foibles and habits of their cats. And, similarly, cats get to know the routines and habits of their owners. When human habits change, or when a cat’s surroundings are different, it can cause stress in cats. However, sudden changes in a cat’s demeanor could also be a sign of ill health.

Look for other signs to help identify the cause of weird cat behavior and, if necessary, have your cat checked by a vet to eliminate illness as a cause of the changes.

See also:


Featured Image Credit: Wanwajee Weeraphukdee, Shutterstock

Want content like this delivered to you?

Sign Up For Our Newsletter

News, insights, expert advice, and everything cat

* By submitting, you agree to our Terms & Conditions and Privacy & Cookies Policy.




How useful was this post?

Click on a star to rate (you can leave written feedback after clicking submit)

Help us improve Catster for pet parents!

Your feedback really matters.

What did you like about this post? Also how can we improve it?

Join the conversation

Leave a Reply

You’re very welcome to leave a comment or question. Please know that all comments must meet our community guidelines, and your email address will NOT be published. Let’s have a positive and constructive conversation.


Catster's Digital Magazine is Back!

Vet-approved health & behavior advice

Real cat stories & community features

Everything I Need to Know About Cartoon Comedy, I Learned From My Pets

If you’ve ever looked at your cat doing something ridiculous and thought, “There has to be a joke in that somewhere,” Scott Metzger...

Chatting About the Rainbow Bridge, Euthanasia, and Laughter During Grief | Chatty Cattys, Episode 24

If you’ve ever felt the loss of a beloved cat, or are dreading the day when your pet crosses the rainbow bridge, you’ll...

The Simple Reasons Cats Refuse to Let Anyone Use the Bathroom Alone

Cats have an extraordinary talent for making themselves present in the most inconvenient places, and the bathroom ranks near the top of the...

A Paw-sitive Milestone: Canada Officially Becomes a Declaw-Free Nation

Canada has officially become a declaw-free nation. On May 25, 2026, a new regulation was filed in Ontario under the Provincial Animal Welfare...

More related

10 Typical Types of Cat Beds (With Pictures)

Cat owners will know that cats all have their own resting and sleeping preferences, and some cats can be rather picky about only...

Why Does a Mother Cat Move Only One Kitten? 4 Vet-Approved Reasons & When to Worry

If your gorgeous cat has just had kittens, it can be an exciting time for you as a pet parent. Despite the urge...

9 Best Cat Cooling Mats and Pads in 2026 – Reviews & Top Picks

We all know that summer can get hot! If you’re without air conditioning, it’s not only hot for you but hot for your...

Ussuri Cat Breed Info: Pictures, Traits & Facts

The Ussuri is a naturally occurring hybrid that originated from Russia in the Amur River region. There is very little information about this...

Keep reading

How to Bond With Your Cat: 12 Vet-Approved Options

Owning a cat is one of life’s great pleasures, but sometimes, it can feel like we need them more than they need us. It can even feel like we’re burdening them with our presence. However, that may not be true....

teenager cat owner cuddling with pet cat

Do Feral Cats Play? Vet-Reviewed Cat Behavior

Feral cats are outdoor cats that have had minimal or no contact with humans and can survive independently or with minimal human intervention. They are typically wary or fearful of people, often scavenging or hunting for food, living in colonies,...

two feral cats

Vet Checklist: What to Bring to Your Cat’s First Visit (Vet-Approved)

Owning a cat is a huge responsibility. In addition to giving excellent care at home, you must also schedule regular vet visits to keep your cat healthy. If your cat’s first vet visit is approaching, the time to prepare is...

veterinarian giving cat's medical record to it's owner

Why Doesn’t My Cat Like To Be Held Or Picked Up? 6 Vet-Reviewed Reasons

No two cats are the same. Just because you’ve owned one in the past or have known somebody else who has owned a cat that loves to be cuddled, that does not mean that all cats like to be picked...

cat doesn't want to be held

Can Cats Eat Mango? Vet Reviewed Nutrition Facts & Safety Guide

Mango is a delicious, nutritious superfood—at least for humans. But what about cats? Maybe your kitty is curious about anything that you eat, or perhaps you just want to add variety to your pet’s diet. Either way, mango is safe...

Can Cats Eat Mango

Vestibular Disease vs. Stroke in Cats: What’s The Difference? Vet-Approved Insights

Strokes in cats are very rare. The symptoms that cat owners most often associate with a “stroke” in cats result from vestibular disease. However, veterinarians may describe the vestibular disease as a “stroke” to aid the pet parents in understanding...

vet holding burma cat

Why Does Cat Pee Smell Like Ammonia? 5 Vet-Reviewed Reasons

Cat owners who use effective cat litter and clean the litter box frequently don’t tend to have issues with cat urine odor. However, some cat owners still struggle to manage the prominent odor of their cat’s urine. So what is...

woman covering nose while cleaning the litter box

11 Best Cat Foods for Sensitive Stomachs & Vomiting in 2026 – Reviews & Top Picks

We all know just how finicky kitties can be when it comes to eating. But aside from their pickiness, others can have quite sensitive bellies that don’t react well to certain ingredients. Since cats are obligate carnivores, eating diets full...

cat lying near bowl with food

Love Cats? So Do We! Join the Catster Community

Stay informed with expert pet care insights delivered straight to your inbox! Discover professional guidance on animal behavior, feeding tips, trusted product picks, and much more.




Sign up for the Catster Email Newsletter

Stay informed with expert pet care insights delivered straight to your inbox! Discover professional guidance on animal behavior, feeding tips, trusted product picks, and much more.