Why You Can't Sleep When You're Exhausted & What to Do about it

Sleep disturbance is a completely predictable response to what your mind and body have been through, and once you understand why it's happening, you have a much clearer path toward changing it.

Nothing is more impossible to sustain, it feels, than a continued failure to sleep. I have been both the lead of an NHS sleep service and suffered from insomnia myself, at the same time - at one point! Sleep disturbance and trauma, can go hand in hand - and how we try to manage that can lead to the problem getting worse. In this article, I try to summarise what we know works - and some broader ideas that might help you.

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You are exhausted. Properly exhausted, the kind that sits in your bones. And yet here you are, wide awake, mind moving, body tense, watching the hours tick by.

If this is familiar, you are not alone. Disrupted sleep is one of the most common experiences for people recovering from relationship trauma, and one of the least talked about. It can feel like yet another thing that is wrong with you. It isn't. It is a completely predictable response to what your mind and body have been through, and once you understand why it's happening, you have a much clearer path toward changing it.

Why Exhaustion and Sleep Don't Always Go Together

Most people assume that being tired enough will eventually override everything else and pull you into sleep. In ordinary circumstances, that is roughly true. But sleep is not just about being tired. It requires a specific set of conditions inside the body, and exhaustion alone does not guarantee them.

For sleep to happen, two things need to be in place. Your body needs to be in a low-arousal state: heart rate settling, muscles releasing, breathing slowing. And your mind needs to let go of active, effortful thinking. When either of these is missing, sleep becomes difficult. When both are missing at once, which is very common after prolonged stress (and trauma), you end up in what researchers call an arousal mismatch: the drive to sleep is high, but the conditions for sleep are not met. Your system is simultaneously exhausted and activated. You want to sleep. Your body won't cooperate.

This is not insomnia in the traditional sense of simply not feeling sleepy. It is a nervous system stuck in alert mode, doing its job of keeping you ready for the next threat, at the very moment you most need it to stand down.

What Relationship Trauma Does to Sleep

During a prolonged period of stress or threat at home, your brain and body adapted. They learned to stay vigilant, to sleep lightly, to surface quickly at sounds or movements that might signal danger. For many people, this meant years of disrupted sleep long before the relationship ended.

When the immediate situation changes, that adaptation does not automatically undo itself. Especially if control / abuse has continued, post-separation. The nervous system remains in a state of readiness. And now, in the quiet of a room that should feel safe, the mind often becomes the source of the threat instead.

Two main patterns tend to disrupt sleep after relationship trauma.

The first is physical arousal. This is the tired-but-wired state: stress hormones that haven't fully cleared, a body that cannot downregulate even when the conscious mind wants to rest. You can read more about this state and why it happens in Why Your Body Won't Settle.

The second is intrusive thinking. The moment the busyness of the day stops, thoughts that have been held at bay start to surface. Conversations replay. Worries about the children, money, legal processes, what the future looks like. The mind treats the silence of the bedroom as an opportunity to process everything it didn't have space for during the day. This is a version of the looping pattern explored in Why Your Mind Won't Stop Looping. At night it tends to feel more intense, partly because there are fewer distractions and partly because a tired brain is less equipped to manage difficult thoughts.

These two patterns often appear together, and they reinforce each other. A body in a heightened state makes the mind more prone to anxious thinking. An active, worried mind keeps the body in a heightened state. The result is a cycle that can be hard to interrupt without knowing which part to address first.

What Actually Helps

There is no single fix for disrupted sleep after trauma, and anyone who tells you otherwise is oversimplifying. But there is a clear, evidence-based sequence of approaches that, used consistently, makes a real difference.

The key word is consistency: sleep responds to patterns, and the nervous system needs repetition before it starts to update its defaults.

Start With the Body

Because of the arousal mismatch described above, the most important first step for most people is not cognitive, it is physical. You need to give the body a signal that it is safe to come down, before the mind is likely to follow.

The most direct and accessible way to do this is through the extended exhale: breathing out for longer than you breathe in. When you extend the exhale, you directly activate the calming branch of your nervous system. Your heart rate begins to slow. The physical tension held in the body starts to ease. The shift can be subtle at first, but it is real and measurable.

To use before sleep:

Lie down in a comfortable position. Breathe in through your nose to a count of four. Breathe out slowly to a count of six or eight, as if breathing through a small gap. Repeat for eight to ten cycles, or more. I often recommend 10 minutes plus.

You can move from this into coherence breathing (five counts in, five counts out, steady and smooth) if you find it easier. Some people find that ten minutes of this, in bed with the lights off, is enough to bring the body to a place where sleep can come. Others find it useful as a bridge into the cognitive approaches below.

Address the Thinking

If thoughts are active once the body begins to settle, the goal is not to stop them. Trying to stop thoughts at night is counterproductive and usually makes them louder. The goal is to change your relationship with them: from engaged and effortful to observational and detached.

A few approaches that have good evidence behind them:

Write it down before bed. Keep a notebook by the bed and spend five minutes writing down anything that is circling: worries, things to remember, unresolved feelings. This is not journalling in the expressive sense. It is offloading: giving the brain permission to stop holding onto things because they have been recorded somewhere. Research consistently shows that this reduces the frequency of intrusive thoughts during the night.

Schedule your worries. This sounds strange but works well. If you find yourself thinking about a particular problem at 2am, remind yourself that you have a time set aside for this tomorrow (even if you haven't yet, the act of deferring is effective). The brain is more willing to release a thought when it believes the thought will be returned to.

Use a body scan. Rather than trying to think your way to calmness, move your attention slowly through the body from feet to head, noticing sensation without trying to change anything. This occupies the attentional system with something concrete and non-threatening, and gradually draws focus away from thought content. It is not about relaxing each body part, just noticing it. The attention tends to settle naturally as it moves.

Sleep Hygiene: The Foundations

These are the environmental and behavioural conditions that support sleep. They are not glamorous and you will likely have heard some of them before. They are worth listing because they are genuinely effective, especially when the nervous system is already under pressure, and because consistency with them reduces the overall load on a system that is already working hard.

Keep a consistent wake time. This is the single most evidence-supported sleep intervention available. Going to bed at the same time matters less than getting up at the same time, including at weekends. This anchors your body's internal clock and, over time, strengthens the natural sleep drive.

Keep the bedroom for sleep. If your brain associates the bedroom with lying awake anxiously, it will begin to anticipate that state when you enter the room. This association weakens over time when you use the bed only for sleep. If you have been lying awake for more than twenty minutes, get up and do something calm in low light until you feel genuinely sleepy, then return.

Wind down for at least thirty minutes before bed. Screens, difficult conversations, and anything that requires active decision-making all keep the alert system running. Give your nervous system a transition period. This might be a warm shower, gentle stretching, reading something undemanding, or the breathing practice described above.

Limit caffeine after midday. Caffeine has a half-life of around five to six hours, meaning half of a midday coffee is still in your system at 6pm. For a nervous system already prone to activation, this matters more than it would in a lower-stress period.

Keep the room cool and dark. Sleep is physically easier in a cool, dark environment. Blackout curtains and a slightly open window, or a fan in warmer months, are straightforward changes that support the body's natural drop in temperature at sleep onset.

Be careful with alcohol. Alcohol may help you fall asleep but significantly disrupts sleep quality in the second half of the night, reducing the restorative deep sleep your body most needs. For people in the wired-but-tired state, this can amplify rather than resolve the problem.

They are all simple - but we can find that we have learned habits that are difficult to break. Especially bed times, waking times and phone use. Not being able to sleep often leads people to stay up later, get up later, stay in bed awake (trying to sleep) and passing the time on screens. All of these can make sense - but they all damage our sleep structure.

A Word on Patience

Sleep is one of the slower things to come back after a prolonged period of stress. The nervous system needs time and repetition to rebuild its sense of safety at night. Progress tends to be gradual and non-linear: a few better nights, then a harder one, then more better nights. This is normal and does not mean the approaches are failing.

What most people find is that the first thing to shift is the quality of sleep rather than the quantity: sleeping more deeply, waking feeling slightly less depleted, recovering more quickly after a disrupted night. Quantity usually follows.

Be patient with yourself in this. Your sleep was disrupted for understandable reasons, over a real period of time. Recovery is not instant. But it is possible, and the direction of travel, with consistent practice, is toward it.

Having seen many people recover from sleep, and my own experience - I know that progress can be up and down / disturbed by new challenges in life. Realise that the body can cope really well even with low sleep, and that trying to accept the journey towards better sleep means you have to do all of the above and then trust the body to sleep when it can. The weirdest thing about trying to sleep, is that you have to give up trying - create the best opportunity and then accept whatever happens!

References / Evidence Base

• Harvey, A. G. (2002). A cognitive model of insomnia. Behaviour Research and Therapy.

• Espie, C. A. (2002). Insomnia: conceptual issues in the development of CBT. Psychological Bulletin.

• Walker, M. (2017). Why We Sleep. Scribner. (Accessible overview of sleep science including cortisol, arousal, and recovery.)

• Germain, A. (2013). Sleep disturbances as the hallmark of PTSD. American Journal of Psychiatry.

• Zaccaro, A. et al. (2018). How breath-control can change your life. Frontiers in Human Neuroscience.

• Porges, S. W. (2011). The Polyvagal Theory. Norton.

• Scullin, M. K. & Bliwise, D. L. (2015). Sleep, cognition and normal aging. Perspectives on Psychological Science.

• Borkovec, T. D. (1982). Insomnia. Journal of Consulting and Clinical Psychology. (On pre-sleep cognitive arousal.)