Why Is My Cat Hissing At Me All of a Sudden? 5 Top Reasons

I remember when my cat hissed at me for the first time. I was extremely taken aback and upset. Hissing isn’t a good sign and is what cats do when they’re being aggressive. So why was my feline friend so annoyed at me? Why is my cat hissing at me all of a sudden when she never has before?

As it turns out, you shouldn’t take this behavior personally. If your cat is hissing but friendly, you can be pretty sure they like you. It is something else in their environment that is causing them to feel threatened and act in an aggressive way.

There are several causes of aggression in cats. In this article, I look at the five most common: territorial aggression, feeling threatened, being in pain, petting-induced aggression, and redirected aggression. Plus, my top tips on what to do when your cat does hiss at you all of a sudden.

Why Is My Cat Suddenly Hissing at Me?

If your cat is hissing at you, there is something that is bothering them. Even the friendliest cats in the world will hiss occasionally if they feel threatened, upset, or overwhelmed. Below are the five most common causes, so take a look and see which you think could apply to your situation.

1. They’re Being Territorial

Cats are naturally very territorial creatures and aren’t afraid to act a little aggressively to defend their space. Territorial aggression does tend to be more of an issue in male cats vs female cats, but even females can get pretty catty if they are pushed to their limits.

There are a few possible reasons your cat might suddenly feel like their territory has been invaded or is at risk of being taken:

• New Kitten: You’ll often see a cat hissing at a new kitten. Your old cat is used to having your home to themselves, and the new kitten seems like an intruder. This can make your cat on edge and they can hiss at you. Your old cat should adjust within a few weeks but watch for signs of cat depression after a new kitten. If they remain unhappy, speak to your vet.
• Neighborhood Cats: There could be a new cat in the neighborhood that is infringing on your cat’s territory. Even if you have an indoor-only cat, this could be a problem. The sight of another cat outside the window can cause your cat to feel like its territory is being threatened. This can manifest as hissing and aggression towards you.
• Unfamiliar Person: It isn’t just new cats that can cause your kitty to feel like its territory is being taken away. An unfamiliar person entering your home can have similar effects. This person could be a temporary guest or something more permanent like your partner moving in or a new baby.
• Non-Recognition: I never had any issues with my cat bullying my other cat until I took one of them to the vet. When bringing him home, my other cat failed to recognize him! In fact, a cat hissing at the other cat after the vet is pretty common. As they don’t recognize their old pal, they think this is a new cat that is encroaching on their space.

2. They Feel Scared & Stressed

Aggression and hissing are common in cats that are scared and stressed. Cats are pretty sensitive creatures, and so even the smallest changes to their routine or environment can make them feel frightened. However, for cats to start hissing at their owners, the stressor is usually pretty severe. Common examples include:

• Moving to a new home, which is a complete change of environment
• Traveling in vehicles (if you struggle with this, you might want to check out these carriers for cats who hate carriers)
• Rescue cats that are adapting to their new home
• Past traumatic experiences causing minor stressors to evoke extreme reactions

If your cat is feeling scared, they’re not hissing at you to be nasty. It is their instinct to become aggressive when they feel threatened, a natural response that aids their survival. By hissing, they are hoping to ward off the threat. Cats arch their backs to make themselves look larger and more threatening as well to further make their opponent retreat.

3. They’re in Pain

If your cat is hissing at you all of a sudden, there is a good chance they are in pain. Cats are known for being masters at hiding pain, so their aggressive behavior could be one of the first signs that something is wrong. This is again a survival instinct – while cats are in pain they are vulnerable so will become aggressive to protect themselves.

One of the most common examples of pain-causing illnesses is arthritis. You might pick your arthritic cat up to try and cuddle them, but accidentally end up hurting their tender joints in the process. Your cat isn’t angry at you for doing so, they’re angry about the pain they are feeling. I think we’ve all gotten a little cranky when sick or in pain!

However, arthritis is a progressive condition that develops over time. If your cat hisses at you all of a sudden, it is more likely an acute injury or condition. Things like abdominal pain or injuries and infections are much more probable.

It is important to try and work out if there is something wrong with your cat to determine whether a trip to the vet is in order. However, wait until your cat has calmed down a little before taking a look. When you do check for signs of injury or infection, make sure you’re as gentle as possible as to not cause them any more pain. And if in any doubt take your cat to the vet anyway.

4. Petting-Induced Aggression

Petting-induced aggression is one of the hardest forms of aggression for people to wrap their heads around. One minute your cat will be purring and enjoying strokes from you. The next minute your cat is hissing at you and acting aggressively! This leaves you scratching your head asking “Why does my cat bite me when I pet her?”.

The answer to this question is overstimulation. When cats are stroked for too long, the feeling turns from being pleasurable to being downright uncomfortable. Cats will then hiss and gently bite your hand to try and communicate that they want you to stop.

To us, this sudden change in mood and behavior can seem extremely out of the blue. Besides, all cats have different petting limits. One cat might enjoy being stroked for 20 minutes, whereas another can reach its limit after 20 seconds! But when our cat does behave like this it is important to stop petting right away. If you don’t your cat can end up lashing out to stop you.

Therefore, we must pay attention to our cats and learn what their individual limits are. Paying attention to their body language and spotting the early warning signs is the only way to do this. This will help ensure you stop at the first signs of overstimulation.

Below are some of the signals you should keep an eye out for:

• Cats might lick your hand before giving you a gentle bite
• Their tails will thrash back and forth or thump
• You might spot the skin across your cat’s back rippling
• Cats often try and push your hand away from them using a paw
• Their body posture will stiffen, pupils dilate, and ears flatten
• Alongside hissing, your cat might growl and any purring will stop

As I said, you need to stop petting your cat at the first indication of overstimulation. If your cat is sitting next to you, stand up and walk away. Or if your cat is sitting on your lap, let them jump down from it if they want to. You can have another petting session later once your cat has calmed down.

5. Redirected Aggression

The final possible reason why your cat is hissing at you all of a sudden is redirected aggression. This is where your cat is frustrated by something that is outside their reach. As they cannot reach the stimulus directly, they take their frustrations and irritations out on you.

Examples of stimuli that might have annoyed or upset your cat include:

• Seeing a bird or mouse outside the window
• Hearing a loud noise
• Seeing a neighborhood cat walk past
• Smelling an unfamiliar scent

Your cat won’t be able to catch the prey that they have seen or tell the unwelcome neighborhood cat that this is their territory. Likewise, the unfamiliar sounds and smells can make your cat on edge. Their hyperactivity and stress are then channeled towards you. Thus, redirected aggression can cause cats to become extremely unpredictable.

What Should I Do When My Cat Hisses at Me?

Your cat might be hissing at you for all kinds of reasons. And while your cat in no way hates you, it is best to take this hissing as a warning sign. Cats hiss when they are aggressive and if you don’t end up listening to them things could turn physical. You don’t want to receive any nasty injuries or annoy your cat further.

Here are the tried and tested steps I follow to stop my cat biting and attacking me. I suggest you follow the same process next time your cat hisses at you:

• Immediately stop whatever it is you are doing. For example, if you’re stroking your cat you should stop right away. If there is something else obvious that is causing your cat to feel threatened or in pain, take this thing away from them quickly.
• Let your cat have time to cool off. This cool-off period will be a different length for different cats. It will also depend on the severity of the scare they’ve just experienced and how annoyed they are.
• During your cat’s cooling-off period, allow them to hide. It is instinctive for cats to hide when they feel stressed or threatened, and failure to allow this natural behavior can make them more angry, upset, and aggressive.
• Take time to realize that your cat isn’t hissing at your because they hate you. Something just got a little too much for them to deal with, but you cannot take it personally. Once they’ve calmed down they’ll be friendly and happy again.

If you think your cat is hissing because it’s in pain, you also need to take your cat to the vet if you haven’t done so already. They’ll be able to prescribe medication to treat whatever condition is causing them discomfort. Or, at a minimum, they’ll be able to provide effective pain relief to calm your kitty.

Also, never respond to aggression with punishment. For example, shouting at your cat for hissing or hitting them is going to exacerbate the situation. This only gives your cat more reason to become aggressive and could be detrimental to your close relationship.

MY FINAL THOUGHTS

If your friendly cat is hissing at you all of a sudden, try not to take it to heart. There are a few possible causes and something has clearly upset your cat. However, once you work out what is causing your cat to react this way their aggression is pretty straightforward to fix.

Your first point of call should always be your vet, just to make sure that nothing is seriously wrong with your cat. If they are injured or sick, treatment is vital. Once they have made a recovery back to full health, any related aggression towards you and others should stop. And if there is nothing wrong, at least you have peace of mind.

Once you’re sure your cat is okay, you can then work to remove the other stressors that are causing your cat to hiss at you. I recommend talking to a behavioral specialist if you can’t figure out what is wrong. Together, you can get to the bottom of your cat’s aggressive behavior.