Why You Feel Tired but Can’t Properly Switch Off in Your 40s

There are days where I feel as though I could crawl into bed and sleep for hours, yet at the very same time can’t seem to properly let myself stop.

I find myself standing in the living room with the sense that there must be something I should be doing, only I can’t quite land on what that thing is. I move between tasks without properly engaging with any of them. I pick up my phone, put it back down, open tabs on my laptop and forget why I opened them in the first place. My body feels tired, my thoughts feel scattered and rest itself starts to feel strangely difficult to access.

Many women experience some version of this in the days before their period begins, although few would necessarily connect it to physiology. More often, it is interpreted as poor motivation, emotional instability or an inability to cope properly with normal life. What is rarely explained is that this state often reflects a very real shift in the relationship between hormones, the nervous system, blood sugar regulation and the stress response.

In the late luteal phase, which is the phase between ovulation and menstruation, progesterone begins to fall quite rapidly. Alongside its role in the menstrual cycle, progesterone also has important effects on the nervous system, particularly around calming and buffering neurological activity. It interacts with receptors in the brain associated with relaxation and emotional steadiness, which is one of the reasons many women notice a distinct change in how they feel as levels begin to decline.

As this hormonal buffering narrows, the nervous system often becomes more sensitive to internal and external demands. Her sleep may become lighter and less restorative like she’s just skimming the edges of sleep but not fully dropping into it. Her blood sugar fluctuations can feel more pronounced and loud environments, cognitive load and emotional pressure may suddenly require far more effort to tolerate. A delayed meal that would barely have registered a week earlier can now leave her shaky, overwhelmed or unable to think clearly or as I sometimes say, in the red zone.

For women who have spent years functioning from adrenaline without necessarily recognising it, this phase can feel particularly uncomfortable.

The body becomes remarkably skilled at carrying women through exhaustion. Cortisol and adrenaline step in to maintain momentum when recovery has not fully happened, meals have been inconsistent or the nervous system has spent long periods in a state of low-grade vigilance. In many cases, this adaptation becomes so normalised that women no longer recognise it as stress physiology. It simply becomes “how life feels”.

Then the late luteal phase arrives, and the body becomes less willing to compensate quietly.

What many women describe during this window is not straightforward tiredness. It is a state of simultaneous depletion and activation where the body is asking for restoration while the nervous system continues behaving as though it still needs to remain alert. This is why she can feel deeply exhausted while also finding it difficult to sit still, rest properly or disengage from the sense that she should be doing something.

This experience is often heightened in our thirties and forties, particularly during perimenopause, when hormonal fluctuations become less predictable and the nervous system becomes more reactive to changes that were previously buffered with greater ease. Women who once managed irregular meals, poor sleep and sustained output without obvious consequences often begin noticing that the same patterns now affect them very differently.

Her concentration becomes harder to hold; motivation feels inconsistent and her emotional resilience narrows. Her sleep no longer restores in the same way and the body begins signalling more clearly that its capacity has changed.

None of this means something has “gone wrong”. In many ways, it reflects a nervous system that is becoming less willing to override its own needs indefinitely.

This matters because interpretation shapes response. A woman who believes she is failing will often respond by pushing harder, becoming more self-critical or attempting to force productivity through exhaustion. A woman who understands that her physiology has shifted is more likely to recognise the importance of rhythm, nourishment, rest and nervous system support before reaching complete depletion.

There is also something really important about simply having language for these experiences. So many women move through this phase privately, assuming they are uniquely incapable of coping with ordinary life, while never realising how many others are standing in their kitchens, living rooms and workplaces feeling the exact same contradiction of being utterly exhausted yet strangely unable to stop.

Understanding the physiology underneath the feeling does not remove the experience entirely, although it often changes the relationship to it. What once felt confusing or self-critical to her begins to make sense within the wider context of her hormones, nervous system sensitivity and cumulative load.

Sometimes that understanding alone is enough to replace self-judgement with a different kind of attention altogether.