More About Obsessions

Obsessions are repetitive mental thoughts, images or impulses. While there are many different types of obsessions, the obsessions of OCD have some clear characteristics:

Obsessions are unwanted & intrusive.

OCD obsessions just “pop in” to our stream of thought, not because we have chosen to think about them.

Obsessions are resisted.

The unpleasantness of obsessions means that there are attempts to avoid triggers or suppress obsessions with compulsions.

Obsessions are uncontrollable.

There is a lot of difficulty in trying to stop obsessions so they can feel overwhelming and uncontrollable.

Obsessions are distressing.

Obsessions are not about lovely or pleasant thoughts but are unacceptable or frightening, and so they are associated with distressing feelings

Obsessions are ego-dystonic.

This means that they are inconsistent with the core values of the self. This is an important one. Obsessions tend to go against the things that are important to you, in fact, they tend to say the very opposite of who you are!

What do obsessions feel like?

There is no one way that people experience obsessions, but below are some of the ways people might describe their experience;

"It just doesn't stop... it feels like my brain won't let me move on."
"It feels like a deep knowing, that it must be true and I need to do something about it"
"The thought keeps coming back no matter what I do."
"It feels urgent, that I need to do something now"
"It doesn't feel like ordinary worrying. It feels more persistent"
"Part of me knows it might not be true but it still feels important"

This is the lived experience of obsessions. They quickly take over your train of thought and demand all of your attention and because they tend to attach themselves to things that feel meaningful or threatening, they are very hard to ignore.

Obsessions are not

Obsessions of OCD tend to feel very convincing. Understanding what they are not can be just as important as understanding what they are.

Obsessions are not wishes: Having an intrusive thought about something does not mean you want it to happen. IN fact, the thought is usually so distressing precisely becuase it is the opposite of what you want to happen.
Obsessions are not predictions: Just because your brain imagines something doesn't make it likely. OCD is sneaky and likes to exploit our imagination but imagination is not evidence.
Obsessions are not intuition: OCD often disguises itself as a feeling or instinct that something is wrong, or that you need to check. This is not intuition but a false alarm.
Obsessions are not memories: False Memory OCD can create powerful doubt about events that may never have happened. Our mind can generate vivid impressions of something without any real evidence that it occurred.

Why are obsessions so upsetting?

OCD is the Disorder of Doubt. It demands our immediate attention by presenting distressing intrusions that feel important or threatening. Because the brain is biased toward noticing negative information, we’re more likely to emotionally react to these thoughts, especially when they go against our sense of self (ego-dystonic).

Sometimes this brain process can serve us well, but in OCD it is overactive and no longer helpful.

Why does this thought get stuck?

Given that we all many thoughts over the course of a day, why is it that our mind can fixate on one particular thought?

This isn't random but by design. OCD has a pattern whereby it will direct our mind to latch onto the things that matter most to us - the people we love, our sense of identity, our morals and values and the things we feel personally responsible for. This means that OCD thoughts usually strike at the very core of who we are and what we care about.

OCD doesn't choose random topics. It chooses ones that are specifically important to us! This is why unwanted intrusive thoughts can be so easy to misread. People often assume that having a disturbing thought means something true about the essence of who they are deep down. In reality, it usually means the opposite. The thought is distressing because it conflicts so deeply with your values, not because it reflects them.

It is no surprise that a person who doesn't care about being a good parent is rarely tormented by fears of harming their child. A person without a moral compass doesn't lie awake plagued by thoughts of doing something wrong. OCD uses what you care about most against you.

Why does OCD feel so convincing?

OCD is the Disorder of Doubt and one of the most disorienting parts of it is that the thoughts don't just feel possible, they feel meaningful and as though the very fact that the thought showed up in the first place says something important about you, or about what might happen next.

OCD is very sneaky in creating a false sense of importance, urgency and responsibility. It tells you this thought must be solved right now, even when there is no evidence that anything is actually wrong.

The thought isn't the problem the cycle is. When we engage with an OCD thought by analysing it, reassuring ourselves, avoiding the trigger, or trying to reason our way out of it we aren't actually resolving anything. We are training our brain that this type of thought deserves attention, and so it keeps returning. The problem isn't the thought itself but our quest for reaching certainty about something that, by nature, cannot be resolved with certainty.

To highlight this process, think of the OCD process as just like a social media algorithm; the more you engage with any type of content (to argue with it, fact-check it, or try to make it disappear) the more the algorithm reads that as interest. The algorithm doesn't know that you are distressed, it just knows that you stopped and paid attention and so it serves you more of the same.

OCD works the same way. Every time we take a thought seriously and try to neutralise it, we send a signal to our brain that this matters! Keep me alert! Keep me updated! and our brain obliges.

The way out of the OCD cycle isn't to engage more cleverly but to learn to starve the OCD attention beast. When we allow a thought to be part of our experience without responding (no solving, avoiding or reassuring) we begin to retrain our brain. Gradually, we learn that these thoughts don't require our attention or action, and it stops flagging them as urgent.

That process isn't easy. But it is the foundation of how OCD gets better.

Obsessions can be Thoughts, Images or Urges

Many people assume OCD only involves a thought in words but actually obsessions can take many different forms, and not recognising them can delay understanding and treatment.

Obsessions can appear as:

Thoughts: a word, phrase or sentence that arrives uninvited
Mental images: a visual scene or picture or flash that the mind generates
Urges: a sudden impulse to do something, with no desire to actually act on it
Impulses: a fleeting sense of being "pulled" toward an action (this is a form of urges)
Doubts: an ongoing uncertainty about whether something happened or is real (this is a form of thoughts)
Sensations: a physical feeling of wrongness, incompleteness or contamination (a form of urges)

Someone who experiences a sudden mental image, an uncomfortable physical sensation, or an inexplicable urge is not experiencing something different from OCD but experiencing OCD in one of its many forms.

If everyone has intrusive thoughts, why do only some people have OCD?

Research consistently shows that unwanted intrusive thoughts are largely considered to be a normal part of human experience. Most people have them but not everyone recognises that they have them because their mind might let the thought pass without any engagement.

So what makes OCD different? It isn't the thoughts themselves. It's what happens next. In OCD, an intrusive thought doesn't just pass. Instead...

the thought is given meaning: "This thought means something is wrong."
the thought feels urgent: "I need to deal with this now."
compulsions are used to manage the distress: checking, reassuring, avoiding
Certainty becomes the goal, even though certainty is impossible to reach

This is the cycle that turns the unwanted intrusions that we all have into obsessions of OCD. The unwanted thought is the starting point, but it is our engagement with the thought that turns them into an obsession.

Common examples of unwanted intrusive thoughts

Intrusive thoughts are far more common than most people realise. Some of the most frequently reported intrusions that include:

Walking across a bridge: "What if I jumped?"
Holding a baby: "What if I dropped them?"
Driving: "What if I hit someone without realising?"
In a church or sacred space: "What if I swear out loud?"
In the kitchen: "What if I picked up that knife?"
At a computer: "What if I accidentally sent that email?"

If any of these sound familiar, you are not alone and you are not dangerous. These thoughts occur to people precisely because they are frightening, not because they are desired.

Common OCD Themes

Why trying not to think about it makes it worse

One of the classic experiments used in OCD research to show the futility of controlling our thoughts is the "white bear" experiment (or "pink elephant" experiment). Let's highlight how this works:

Right now, try not to think of a white bear.

Notice what happens.

Were you successful in keeping a white bear out of your mind?

Usually we find the opposite. That instruction to avoid a particular thought almost always backfires. This is because when we try to push a thought away, we are essentially telling our brain to "keep watch" to make sure you are not thinking about it. That monitoring means the brain is scanning for the thought constantly. The result is that you notice it more, not less. When a thought keeps reappearing despite your best efforts to stop it, the brain draws a conclusion that this must be important.

This process shows that the we try to suppress a thought, the more it returns. Suppression doesn't protect you from the thought it trains your brain to treat it as a threat worth watching.

OCD intrusions work like a mozzie bite

Think of an intrusive thought like a mosquito bite (or mozzie bite for us Aussies). The itch is real and uncomfortable, and scratching brings some immediate relief. But scratching doesn't resolve it, it actually inflames the area, makes the itch more intense, and keeps drawing your attention back. The more you scratch, the more it demands to be scratched.

OCD works the same way. The thought arrives and creates discomfort. The urge to analyse it, resolve it, or make it go away feels completely reasonable like scratching an itch. But every time we engage, we inflame it further. The thought doesn't settle; it intensifies.

Leaving a bite alone feels almost unbearable, but the less we engage, the more likely the uncomfortable sensation will dissipate

More about compulsions

The Emotions Behind Obsessions

OCD is commonly associated with anxiety and indeed, OCD was once considered to be a form of anxiety disorder. But anxiety is only one of the emotions it can produce. Many people don't recognise their experience as OCD because what they feel doesn't fit the word anxious. Understanding the full range of emotions obsessions can generate helps people identify what they are actually experiencing.

Anxiety, Fear and Panic

This is the most commonly recognised emotional response to obsessions. It can range from a low-level hum of unease all the way to full panic. The mind perceives the thought as a real threat and the body responds accordingly, flooding the system with adrenaline and urgency. The feeling is that something terrible is about to happen, or may already be happening, and that it must be addressed immediately.

Unease / The "Not Right" Feeling

This is one of the hardest emotions to describe, and one of the most commonly misunderstood. It isn't quite anxiety, and it isn't quite fear but it is persistent sense that something is off, that things aren't quite right or that something is unresolved or incomplete. This feeling often drives compulsions not to reduce danger, but to relieve the discomfort of wrongness and relief only ever lasts a moment before the feeling returns.

Anger and Irritability

OCD is mentally exhausting. When someone has spent hours managing intrusive thoughts, suppressing doubts, and performing compulsions (often invisibly), it is common to feel short-tempered, reactive or on edge. This irritability is not a character flaw. It is the result of a nervous system that has been running on high alert for too long. Anger can also be directed inward, particularly when someone feels frustrated that they cannot simply stop thinking something.

Stress and Overwhelm

Some people don't experience fear so much as an exhausting, relentless pressure. The thought never quite goes away. It sits in the background of every conversation, every task, every attempt to rest. Over time, this constant mental load creates a deep sense of overwhelm, not because of any single thought, but because of the cumulative weight of never being fully free of it.

Disgust and Aversion

For some obsessions, particularly those involving contamination, unwanted sexual thoughts, or morally distressing images, the primary emotion is disgust rather than fear. This can feel physical: a sense of revulsion in the body, an urge to recoil or get away. Disgust-based OCD is often underdiagnosed because people don't connect a feeling of repulsion with an anxiety disorder. But disgust functions in the same cycle: the more it is avoided and neutralised, the more powerful it becomes.

Sadness and Worthlessness

Living with intrusive thoughts, especially when they remain hidden, can be profoundly isolating. When OCD targets identity or morality, people often carry a deep, quiet shame: what kind of person thinks these things? Over time, this can develop into a sense of worthlessness, hopelessness, or low mood. Depression and OCD frequently occur together, in part because of how demoralising it is to struggle with something the rest of the world seems to manage without effort.

Common Physical Responses

Our body responds to the threat-signal of obsessions in real, physical ways. These sensations are produced by our nervous system and is our body doing exactly what it is designed to do when it perceives a threat.

Increased Heart Rate

The heart speeds up as the body prepares to respond to a perceived danger. This can feel alarming in itself (particularly for people with health anxiety) and can intensify the sense that something is seriously wrong.

Dizziness

Rapid or shallow breathing, which often accompanies anxiety, changes the balance of oxygen and carbon dioxide in the blood. This can produce lightheadedness, a sense of unreality, or feeling unsteady. This can leave us feeling like we are losing control which further intensifies the experience.

Gastrointestinal (GI) upset and nausea

The gut is deeply connected to the stress response. Anxiety commonly produces nausea, stomach cramps, loose stools, 'butterflies in the stomach' or a general unsettled feeling in the digestive system. Many people don't connect these physical symptoms to their mental state but GI symptoms are closely linked to stress.

Difficulty concentrating

When the nervous system is activated, the brain narrows its focus toward the perceived threat. This makes it very hard to sustain attention on almost anything else (e.g., work, conversations, reading) because part of the mind is always being pulled back to the threat.

Urge to urinate or defecate

The body's stress response diverts resources and can activate the bladder and bowel. A sudden or urgent need to use the bathroom in moments of high anxiety is extremely common and physiologically normal.

Nerve activation/twitching and groinal responses

The nervous system can fire in unexpected ways under stress, producing involuntary muscle twitches or sensations in the body. A particularly distressing and poorly understood example is the groinal response (an unwanted physical sensation in the genital area that can occur in response to an intrusive thought, particularly sexual or POCD-related obsessions). This is a nervous system reaction, not an indicator of desire or intent. It is one of the most shame-inducing symptoms of OCD, and one of the least talked about which means many people suffer alone, believing the sensation confirms their worst fears. It does not.

What about other types of obsessions?

The above characteristics are important because they help to distinguish the obsessions of OCD from other types of obsessions. For instance, being “obsessed” or in love with something (philia) is different to an OCD obsession because it is in line with how the person feels (ego-syntonic), and there may even be pleasure associated with the thoughts.

Frequently Asked Questions

Why won't the thought go away?

Because engaging with it (analysing it, reassuring yourself, or trying to suppress it) signals to the brain that it deserves attention. The brain keeps returning to things it believes are unresolved. In OCD, the attempt to resolve the thought is what keeps it returning.

Does having an intrusive thought mean I want it?

No. The distress caused by the thought is usually evidence of the opposite. Intrusive thoughts tend to be distressing precisely because they conflict with what you actually want and value.

But I have the thought and it doesn't distress me anymore... does that mean it isn't OCD?

Not at all. It may actually mean the opposite: that you are beginning to respond to the thought differently. When we stop giving an intrusive thought significance (stop analysing it, fighting it, or trying to resolve it) the emotional charge it carries tends to reduce. That's not a sign something is wrong. That's recovery working and is what we aim for in treatment.

Distress is a useful early signal that a thought is unwanted. But it isn't the only one. If the thought arrives and you find yourself thinking I wish this wasn't here (even calmly, even without panic) then that is tells us enough. The measure of whether a thought is unwanted isn't how much it frightens you. It's whether you'd choose to have it if you had the choice.

A reduction in distress around an intrusive thought is something to notice with curiosity, not alarm.

Can OCD make thoughts feel real?

Absolutely!! OCD creates a powerful sense of urgency and significance around certain thoughts. This can make an imagined scenario feel far more credible than it actually is.

Why do I keep doubting myself?

Ahh well this is because OCD is the Disorder of Doubt. It is masterful at targeting the things you feel most uncertain about and makes certainty feel permanently out of reach because in OCD, the goal is not to provide certainty, but to keep you seeking it.

Can OCD create false memories?

Yes and this isn't an OCD thing... any human brain can create false memories. An OCD core them called False Memory OCD involves persistent doubt about whether something happened (often something distressing) despite little or no evidence that it did. The brain can generate the feeling of a memory without the memory being accurate.

Why can't I stop analysing?

OCD is very convincing in having us feel as though one more round of thinking will finally deliver the certainty that resolves the doubt. But in OCD, analysis only deepens the cycle. Certainty is always just out of reach. I often tell my clients "you can't think your way out of OCD" because OCD will always one-up us with another new doubt.

Are intrusive thoughts dangerous?

Are any thoughts actually dangerous? No! Intrusive thoughts are thoughts, they are not actions, intentions or predictions. Research consistently shows that people who experience disturbing intrusive thoughts are no more likely to act on them than anyone else.

Can OCD make me feel guilty?

Yes. Guilt is one of the most common emotions in OCD, particularly in moral and religious subtypes. The guilt is real, even when there is nothing to feel guilty about.

Are intrusive thoughts normal?

Yes. Research has found that the vast majority of people experience intrusive thoughts from time to time. What distinguishes OCD is not the presence of these thoughts, but the way they are interpreted and responded to.

Printable Handout

Because OCD obsessions are so uncomfortable, the brain seeks out ways to reduce distress, or prevent something bad happening.

The compulsions of OCD are designed to help you feel better...

Learn More About Compulsions

Compulsions are designed to make you feel better, but they actually make OCD worse.
More on this when we introduce CBT for OCD.

Additional Resources

For further information, patient education materials, and evidence-based resources on OCD assessment and treatment, explore the related pages on OCD Online, including: