Why Is My Brain So Noisy?

You sit down to finish one thing.

Then you remember the email you haven't replied to...

Which reminds you of the appointment you need to book...

Then, for no apparent reason, you're wondering whether you closed the garage door.

A few minutes later, the thing you originally sat down to do is still waiting.

It can feel like having 20 tabs open in your brain, and they’re all continuously reloading.

For some people, this can feel like a "noisy brain."

Thoughts compete. Concentration feels harder. Your mind jumps ahead, doubles back or brings something completely irrelevant into focus at exactly the wrong moment.

And it's easy to wonder whether that feeling means something specific.

Do I have ADHD? Is this anxiety? Is this brain fog? Is this just what happens as I get older?

They're understandable questions to ask, because attention and mental clarity can be affected by lots of different things.

- ADHD can affect the regulation of attention and executive function.⁽¹⁾
- Depression has been shown to negatively impact neurocognitive functions. ⁽²⁾
- Fluctuations in hormone levels during peri/menopause can affect cognition.⁽³⁾
- The brain will change as we get older. And that may impact recall and memory.⁽⁴⁾

So there are very real biological and psychological reasons why someone might experience changes in attention, clarity or the amount of mental "noise" they feel.

But those experiences aren't specific to any one condition.

A noisy brain isn't a diagnosis. It's an experience.

And understanding what's happening means looking at the many different things that can influence how our brains filter, prioritise and respond to information.

Why does it feel like every thought is happening at once?

Your brain is constantly filtering.

Right now, there are sounds around you, sensations from your body, objects in your peripheral vision, memories you could retrieve, tasks you need to complete and countless other pieces of information potentially available to your conscious mind.

You can't pay attention to all of them.

So your attention acts a little like a spotlight.

It selects what's relevant and helps competing information fade into the background.

When you're reading an important email, for example, the goal is for the words on the screen to occupy the spotlight — not the conversation across the room, tomorrow's shopping list and the fact that you haven't replied to Sarah.

But that selection process isn't equally easy all the time.

Stress can affect executive functions including working memory and cognitive flexibility. Even a single night of restricted sleep can impair sustained attention.⁽⁵⁾ And when you're already carrying a high cognitive load, there are simply more things competing to get back into the spotlight.

That's when your attention can start to feel less like a spotlight and more like someone rapidly flicking between channels.

Email.
Meeting.
Dinner.
Deadline.
Did I lock the door?

It's not necessarily that you're suddenly generating an extraordinary number of thoughts.

The problem may be deciding which thought deserves your attention — and keeping it there.

Your brain can only keep so much "in mind"

There's another piece of this: working memory.

Working memory is the small amount of information you can temporarily hold and work with. It's what allows you to keep the beginning of a sentence in mind while reaching the end, follow several steps of an instruction, or remember why you walked upstairs long enough to actually get there.

Its capacity is limited.

Now think about what happens on a particularly busy day.

You need to remember to call someone. There's a conversation at work you haven't quite resolved. You need to buy something on the way home. There's a decision you've been putting off. You've got three deadlines approaching. And somewhere underneath all of that is the nagging feeling that you've forgotten something.

None of those things necessarily requires your attention right now.

But they're all potential candidates for it.

This is why getting things out of your head can feel disproportionately relieving. Writing down tomorrow's tasks won’t make them disappear, but it means you no longer have to keep mentally rehearsing them so you don't forget.

Sometimes "clearing your head" is surprisingly literal.

You're reducing the number of things you're asking your brain to keep readily accessible.

ADHD, menopause and the noisy brain

This is also where it's worth being careful about labels.

A brain that jumps between thoughts can be part of the lived experience of ADHD. Research in adults with ADHD has found differences across areas including attention, working memory, inhibition and executive control.

But experiencing distraction or mental noise doesn't, by itself, mean someone has ADHD.

The same applies to menopause.

"Brain fog" is a commonly reported experience during the menopause transition. People may notice changes in concentration, memory or their ability to find words. Research supports the existence of cognitive changes during perimenopause, although the experience varies considerably between individuals and can also interact with factors such as sleep and mood.

So two people can both say:

"My brain feels so noisy lately."

But the processes contributing to that experience may be very different.

That's why the feeling itself isn't enough to tell us the cause.

Why does silence make everything louder?

Here's the strange thing about mental noise:

Sometimes you notice it most when everything else becomes quiet.

You turn the television off.
Put your phone down.
Take your headphones out.

And instead of experiencing glorious mental peace, your brain seems to get louder.

This doesn't necessarily mean silence has created more thoughts.

It may simply have removed everything that was competing with them.

Think about a snow globe just after you've shaken it. There's movement everywhere. Individual details are difficult to see.

Then you put it down.

The snow starts to settle.

The scene underneath hasn't suddenly appeared. It's simply easier to see.

Something similar can happen with our internal experience. Throughout the day, external information is constantly competing for attention: conversations, work, music, podcasts, messages, social media, television.

Remove those inputs and attention has more opportunity to turn inward.

Suddenly you notice the thought that's been hovering in the background.

The conversation you're still replaying, or tomorrow's problem, or the decision you still haven't made.

Silence gives you the opportunity to notice these thoughts.

And that may help explain why we can become so quick to fill every quiet moment.

Waiting for the kettle? Check your phone.
Walking somewhere? Put on a podcast.
Waiting in a queue? Scroll.

None of those things is inherently bad. But if every moment without a task is immediately filled with more input, there are fewer opportunities to simply notice where your attention goes when nothing outside you is demanding it.

Why does my brain go into overdrive at bedtime?

Then comes perhaps the most familiar noisy-brain moment of all.

You get into bed, everything is finally quiet.

And your brain decides now is the perfect time to remember every unfinished task, questionable conversation and responsibility you've accumulated.

There's a reason thoughts can feel more noticeable at bedtime.

During the day, attention is frequently directed towards external goals. You're answering, talking, reading, driving, deciding, reacting and solving.

At bedtime, much of that external demand disappears. There is suddenly far less competing for your attention.

That doesn't mean everyone's brain is secretly storing up the day's thoughts and deliberately releasing them the second their head hits the pillow. But it does create an environment in which spontaneous thoughts, worries and unfinished concerns can become much more noticeable.

And for people experiencing insomnia, research suggests pre-sleep thinking can be particularly intrusive, with planning, problem-solving, worry and cognitive arousal all associated with difficulty falling asleep.(6)

Poor sleep can then add another layer to the problem. Sleep loss itself affects attention and executive function — potentially making the following day feel mentally noisier too.
It can become a frustrating loop:

You're tired, so focusing is harder. Your day feels more mentally cluttered. You get into bed and notice everything still circling. Then the mental activity makes switching off harder.

This is why a wind-down period can matter. Writing tomorrow's tasks down, creating a predictable bedtime routine or giving yourself some quiet processing time before getting into bed may help reduce the amount competing for attention once you're trying to sleep.

Have we forgotten how to be bored?

Modern life gives us something previous generations never had at this scale:

The ability to eliminate boredom almost completely.

There are very few moments when we have nothing to do anymore.

A phone can fill almost any gap with novelty, information or entertainment within seconds.

It's tempting to conclude that this is "destroying our attention spans", but the research is more complicated than that.

Studies looking at heavy media multitasking and cognitive control have produced mixed findings, and we can't simply say that using your phone rewires your brain to become distracted.⁽⁷⁾

But there's still a useful question to ask:

When was the last time you allowed a quiet moment to stay quiet?

If every pause automatically becomes an opportunity for another input, it becomes difficult to know whether you're choosing stimulation because you want it, or reaching for it because being without it has started to feel uncomfortable.

Can you train a noisy brain to feel calmer?

You don't need to empty your mind.

And you certainly don't need to spend hours sitting in silence.

A better goal is flexibility: being able to direct your attention when you need to, notice when it wanders, and become more comfortable with periods when nothing is demanding it.

Start small.

• Take a five-minute walk without headphones.
• Drink your coffee before checking your phone.
• Wait in a queue without automatically scrolling.
• Drive a short journey without putting something on.

Do one task without simultaneously watching, listening to or checking something else.

And support the basic biology that attention depends on.

Sleep matters: research consistently shows that insufficient sleep affects sustained attention and executive functioning.(8)

Regular physical activity, adequate nutrition, time outside and managing chronic stress all form part of the bigger picture of cognitive health.

The aim isn't to create a perfectly silent brain. Thoughts will still appear. You'll still remember something irrelevant halfway through an important task. You'll still occasionally get into bed and suddenly remember an email you should have sent six hours earlier.

That's what brains do.

But you can get better at recognising that every thought doesn't require your immediate attention.