Blog twenty: Understanding your stress threshold: How sensory overload affects your nervous system.

Do you know your stress threshold? That invisible line where the body quietly moves from “I’m handling this” to “this is too much.”

Most of us don’t notice that line while we’re approaching it. We only realise it exists once we’re already past it.

We talk a lot about stress management, resilience, and coping tools. And yes, mindset absolutely matters. How we interpret stress can genuinely change how our body responds to it.

Research from Stanford psychologist Alia Crum has shown that when we view stress as something we can work with, rather than something that will harm us, our physiological response is different. Cortisol patterns are more balanced, inflammatory markers are lower, and recovery tends to be faster.

But here’s the part that often gets missed:

You can have a supportive stress mindset and still have a natural limit to what you can tolerate.

Both can be true.

Stress has a ceiling.

We each have a baseline stress threshold.
A point where our nervous system can no longer adapt, regulate, or stay flexible.

That threshold is shaped by things like:

• Sleep quality

• Hormones

• Nutrition

• Past stress

• Nervous system regulation

• Genetics

• What season of life you’re in

It’s why two people can experience the same situation very differently.
It’s why one week you feel capable and grounded, and the next week the smallest thing feels overwhelming.

Reaching your threshold doesn’t mean you’re weak or “bad at coping.”
It means your system has reached its current capacity.

And capacity isn’t static — it shifts.

Stress tolerance isn’t just mental

We often talk about stress tolerance as if it lives purely in the mind. As if reframing, positive thinking, or pushing through should be enough.

But stress tolerance is largely physiological.

It’s influenced by:

• How regulated your nervous system is

• Whether your body feels safe or on edge

• Blood sugar stability

• Where you are in your menstrual cycle

• How much recovery you’re getting

• And something that’s rarely talked about… sensory load

The role of sensory load

Your nervous system is constantly taking in information.
Light, noise, movement, screens, visual clutter, conversations, notifications, background demands.

Even on days where you haven’t “done much,” your brain may have been working incredibly hard just filtering input.

That filtering takes energy.

When sensory load is high for too long, it quietly eats away at your stress tolerance. Your threshold lowers, not because you’re failing, but because your system is already doing so much behind the scenes.

How I notice my own threshold

For me, my early warning sign isn’t emotional or dramatic.

It’s when my mind feels over-full.

Not overwhelmed in a big obvious way, just full.
Too many tabs open. Too many small decisions. Too much mental noise.

I don’t snap. I don’t melt down.
I just get this clear internal signal of “I can’t hold one more thing.”

That’s my threshold.

When I ignore it, I move into overwhelm. My thinking becomes foggy, I feel disconnected from myself, and everything takes longer than it should. The simplest tasks feel heavier.

When I listen to it early, I can pause and reset before my body has to shout louder later.

Why this matters

Because stress tolerance isn’t about becoming endlessly resilient or learning how to tolerate more and more.

It’s about self-awareness.
Knowing the signs that tell you you’re nearing your edge — and responding with care instead of criticism.

Yes, there are ways to gently support and build stress tolerance:

• Shifting how you interpret stress

• Breathing practices that support the vagus nerve

• Movement that helps clear adrenaline

• Reducing sensory load where possible

• Creating boundaries so your nervous system isn’t constantly “on call”

• Being honest about your capacity today, not in an ideal version of yourself

But none of these tools erase the reality that we all have a threshold, and that threshold changes.

So I’ll leave you with this question:

Do you know the moment where stress stops being helpful and starts being too much for you? That awareness alone can change everything.

Links:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3862900/

https://sparqtools.org/rethinkingstress-research/