The Nights

You probably assumed that when treatment ended, you would sleep.

That the exhaustion of the past months would finally have somewhere to go. That your body, released from the assault of treatment, would simply rest. That the thing you had been craving through every gruelling session — stillness, quiet, a proper night — would finally be available to you, and you would take it.

For some people, that happens. For many it doesn't. For many, the sleep that was broken during treatment becomes, in the weeks and months after it, worse. Not just different in shape. Genuinely worse.

And lying awake at three in the morning, in a silence that contains none of the machinery of active treatment, none of the clinical busyness that at least had the virtue of being something to get through, the experience of cancer at night becomes its own particular thing. Before you've even properly surfaced, your mind has already started the calculation. The awareness of your body that treatment installed doesn't stand down at bedtime. The fear doesn't recognise the dark as a reason to quieten — it recognises it as a reason to get louder, because at three in the morning there is nothing to direct it elsewhere and no rational mind available to hold it in proportion.

And then, because the night was broken, morning arrives harder. The fatigue from the previous chapter is worse. The cognitive fog from the chapter before that is worse. And the night coming — the one that should be a relief — you have started to dread. Because the bed, which ought to be the one place your body goes to recover, has become associated in your nervous system with lying awake, and the dread of another bad night is itself one of the things that causes one.

This is not weakness. This is a loop. A specific, documented, well-understood loop — insomnia feeding fatigue feeding anxiety feeding insomnia — and it has a way out. This chapter is about that way out. And because many people who read this will not have access to a referral, a waiting list, or the internet, everything in this chapter that can be done alone, with nothing but time and attention, is written out fully enough to actually be useful. Not summarised. Not gestured at. Written out.

How common this is — and the treatment gap nobody talks about

Sleep disruption after cancer treatment is not unusual, and it does not resolve automatically. A review published in JCO Oncology Practice in 2024 found that poor sleep affects up to 59% of cancer survivors. A Dutch registry study the same year, comparing cancer survivors to people without cancer across multiple cancer types, found that sleep problems were significantly more prevalent in survivors and — importantly — that this difference did not reduce with time since diagnosis. People years out from treatment were no less likely to be sleeping badly than people one year out.

What makes this worse is what happens when people seek help. A 2024 abstract from the San Antonio Breast Cancer Symposium found that of those cancer patients and survivors with diagnosable insomnia, 86% had not been offered treatment for it.

That is not a small figure. That is nearly nine in ten people with a diagnosable, treatable condition walking away without treatment. The British Sleep Society — the professional body for everyone working in sleep medicine in the UK — has itself acknowledged on its website that sleep services are experiencing significant challenges with rising referrals, a significant backlog and workforce challenges. Sleep medicine has no dedicated training pathway of its own in the NHS. It sits as a subspecialty of respiratory medicine, neurology or psychiatry, which means the number of people for whom sleep is their primary expertise is tiny relative to the need. Waiting lists for sleep clinics can be very long indeed. Most GPs, when someone reports insomnia, offer a sleeping tablet prescription — not because it is the right first-line treatment (the evidence says it isn't), but because the right first-line treatment requires specialist access that in most areas is not readily available.

The practical consequence is that for a very large number of cancer survivors, self-help is not a supplement to clinical treatment. It is what there is. This chapter takes that seriously and treats self-help accordingly — not as a list of suggestions but as a full, usable toolkit.

Why sleep gets worse after treatment — the reasons are specific and worth knowing

Understanding why the nights get harder after treatment ends takes the mystery out of it and, more practically, points toward what actually helps.

During treatment, sleep was broken by specific, acute causes. Steroids given alongside many chemotherapy regimens are stimulating and disrupt sleep architecture for days after each cycle. Pain, nausea, hospital stays, and the general physical distress of treatment all make nights difficult. But there was also something else operating — the adrenaline of navigating something acute, the structure of appointments and clinical oversight, the forward-pulling demand of getting to the next session. All of that held something in place. When treatment ends and the adrenaline lifts, what it was holding begins to arrive.

There is also something specifically neurological happening. Sleep is, in a very precise sense, a learned behaviour. The brain learns when, where and under what conditions it is safe to sleep. Months of broken, disrupted, anxiety-driven nights train the nervous system in the wrong direction. You learn, below conscious thought, to be alert in the night — to surface frequently, to treat waking as the body's default. That learning does not reverse because treatment has ended. It reverses because something teaches the brain a different pattern, and that requires deliberate effort. Time alone is not enough.

Several specific physical drivers also continue long after the last treatment session.

Hot flushes and night sweats — caused by chemotherapy, by hormone therapies including tamoxifen and aromatase inhibitors for breast cancer, and by hormone therapy for prostate cancer — affect the majority of people on those treatments. Research shows they affect 65 to 85% of women after breast cancer treatment. They interrupt sleep at its deepest stage, producing fragmented waking that leaves people feeling unrefreshed regardless of total hours in bed. This is one of the most reliably documented drivers of post-treatment insomnia, and in many cases it goes untreated for years simply because nobody offered anything.

Pain — from surgery, from the musculoskeletal effects of aromatase inhibitors, from neuropathy, from various physical late effects — is consistently associated with poor sleep in cancer survivors. Night pain operates differently from daytime pain and deserves to be raised with your GP as a distinct and specific complaint.

Anxiety runs through all of it. The fear of recurrence described in Chapter 2 is loudest at night, when there is nothing to direct it elsewhere. The hypervigilance that cancer installs in the nervous system does not recognise bedtime as a reason to stand down.

And around all of this, a set of entirely understandable responses develops that entrench the problem. Spending longer in bed to compensate, which dilutes whatever sleep is happening. Napping in the afternoon, which reduces the biological drive to sleep that would otherwise help at night. Beginning to dread bedtime, so that the hour of approaching sleep becomes anxiety-laden. Watching the clock, which turns insomnia into a measurement exercise that adds distress to distress. None of these are wrong choices. All of them make things worse. The reason is not any failure on your part — it is that insomnia is self-reinforcing when you don't have the specific knowledge to interrupt it.

The sleep-fatigue-fog loop — why getting the nights right matters beyond just sleeping

The three things covered in the last two chapters and this one — fatigue, cognitive impairment, and broken sleep — are not separate problems that happen to coexist. They feed each other.

Disrupted sleep directly worsens cancer-related fatigue. The body does most of its repair work during deep sleep — rebuilding immune cells, processing the physiological recovery that treatment has made necessary. When sleep is fragmented and restorative sleep is absent, you wake more depleted than you should, and the day starts at a lower baseline.

Disrupted sleep directly worsens cognitive function. The brain uses deep sleep to consolidate memory, clear metabolic waste that accumulates during waking hours, and restore the prefrontal function that manages proportion and context. Without restorative sleep, the cognitive fog of Chapter 3 is significantly worse. People dealing with both chemo brain and broken sleep are dealing with a combination that is considerably more disabling than either alone.

Anxiety — the engine of insomnia — worsens both. It occupies working memory, reduces the bandwidth available for other thinking, and maintains the physical arousal that prevents restorative sleep.

Breaking any one part of the loop helps the others. Better sleep reduces fatigue and improves cognition. Treating the physical drivers of night disruption — hot flushes, pain — improves everything downstream. This is one of the reasons that getting sleep sorted matters beyond the nights themselves. It is not a comfort measure. It is one of the most impactful things available in the post-treatment recovery.

The treatment that works — and what the NHS can and often cannot offer

There is a treatment for insomnia with better long-term outcomes than sleeping tablets. NICE — the body that determines what is clinically effective for the NHS — recommends it as the first-line intervention for insomnia, before medication or alongside it.

It is Cognitive Behavioural Therapy for Insomnia. CBT-I.

A systematic review and meta-analysis published in 2022, drawing on 22 randomised controlled trials specifically in cancer survivors, found that CBT-I significantly improved insomnia severity with a large effect size — with durable benefits maintained at both 3 and 6 month follow-up. It also produced meaningful improvements in anxiety, depression, fatigue and quality of life alongside the sleep improvements. This is not gentle management. It is a treatment with a solid, specific evidence base.

What CBT-I involves is less complicated than the name. At its core it works on three things simultaneously: rebuilding the learned association between bed and sleep (rather than bed and lying awake being anxious); concentrating and deepening the sleep you do get before gradually expanding the available window; and directly addressing the thoughts and beliefs about sleep that keep the anxiety running. Each of those is covered in practical detail in the self-help section below, because they can all be done without a therapist.

If you want clinical support for CBT-I and can access digital services, Sleepstation — at sleepstation.org.uk — is a digital CBT-I programme available on the NHS in 36 of the 41 Integrated Care System regions in England, as well as in Scotland and Wales. Your GP can refer you, and in many areas you can self-refer using the postcode checker on the Sleepstation website. It is clinically proven, registered as a medical device, and has been running as an NHS-commissioned service for over 13 years. If you have internet access and sleep is significantly affecting your life, checking your area's availability is worth doing today.

NHS Talking Therapies — which you can access by asking your GP for a referral, or by calling your local service directly — primarily works with anxiety and depression but does include CBT-I components in some areas, and the sleep and anxiety dimensions of post-treatment insomnia overlap enough that it is worth asking about specifically.

If you do not have easy home internet access, your local library offers free computer use and staff who can help you get online if that is something you want. Your GP surgery can also make referrals to Sleepstation on your behalf without you needing to go online yourself.

What your GP should not offer as a long-term solution — and the evidence does not support it as one — is simply a sleeping tablet and nothing else. Z-drugs and benzodiazepines sedate around insomnia without changing it. They carry risks of dependence with longer-term use, they do not produce restorative sleep, and they do not address any of the underlying causes. If you are taking sleeping tablets regularly and find they are no longer working, or you are worried about dependence, speak to your GP before stopping — stopping some sleep medications abruptly can cause significant rebound insomnia. But do have the conversation about what else is available alongside or instead.

Self-help that works — a complete guide for anyone, with or without internet

This section is written for everyone. Everything here can be done tonight, from this page, without any referral, waiting list, or internet connection. If clinical support is not accessible to you right now, this is not second-best. Several of these techniques are the active components of CBT-I itself, written out plainly.

Start a sleep diary — the foundation of everything. Before anything else, begin keeping a sleep diary. You need a piece of paper — nothing digital, nothing complicated. Each morning, note down five things from the night before: what time you got into bed, roughly what time you fell asleep, how many times you woke and for roughly how long, what time you finally got up, and a number from one to ten for how rested you feel. Do this for a week before changing anything else. It takes three minutes and it gives you the information you need to understand your actual pattern rather than your fear of your pattern. People consistently overestimate how little they are sleeping when they have not tracked it. The diary often reveals that the situation, while genuinely difficult, is somewhat better than it feels.

Keep your rising time consistent — the single most powerful thing you can do. Choose a rising time and keep to it every day, including weekends, including after bad nights. Set an alarm if you need to. Even if you slept for three hours, get up at that time. This is the hardest instruction in this section and also the most important. Your body runs on a biological clock — the circadian rhythm — that regulates your drive to sleep. Sleep pressure, the biological need to sleep, builds across the waking day from the moment you get up. The longer you are awake, the stronger it becomes, and the stronger it becomes, the better able you are to fall asleep at night. Sleeping late after a bad night resets the clock in the wrong direction — it dissipates the sleep pressure you need for the coming night and makes it harder, not easier. Getting up at the same time every morning, however tired, is the engine that drives improvement in everything else.

Use sleep restriction — the counterintuitive technique that works. Look at your sleep diary after a week. Add up the total hours you actually slept and divide by seven to get your average. This is your sleep window. Set the time you go to bed so that the gap between bedtime and rising time equals your average actual sleep. So if you sleep an average of five hours and rise at 7am, you go to bed at 2am — not before. If you average six hours, you go to bed at 1am. This is called sleep restriction and it is deliberately uncomfortable for the first week or two. It concentrates your sleep — rather than spending eight hours in bed sleeping for five, you spend five hours in bed sleeping for most of them. Your sleep efficiency improves. Your body's drive to sleep deepens. After a week of sleeping well within your window, add fifteen minutes by going to bed earlier. After another week of sleeping well, add another fifteen minutes. Continue gradually until you reach a window that feels restorative. Sleep restriction feels brutal at first. The evenings are long and tiring. The urge to go to bed earlier is strong. Stay with it. This is the technique with the strongest evidence base in CBT-I and the one that produces the most significant and durable results. It is also the one most people abandon too early, because the first week feels worse. If you know in advance that it will feel worse before it gets better, you are much less likely to give up at the wrong moment.

Use the bed only for sleep. Not for reading. Not for your phone. Not for watching television. Not for lying there worrying about whether you will sleep. The brain is very good at learning associations. If the bed is where you spend hours awake being anxious, it learns to activate the arousal system when you get into it. The goal is to rebuild the association between bed and sleep. This means getting out of bed if you have been awake for roughly twenty minutes — not clockwatching, but a sense of it — going to a different room, doing something quiet and undemanding, and returning only when you feel genuinely sleepy rather than just tired and determined. A chair, a sofa, a dim light, something undemanding to read or listen to. Then back to bed. This feels wrong. The instinct when you cannot sleep is to stay in bed and keep trying. Doing the opposite — getting up — is what breaks the pattern.

Don't look at the clock. Turn your alarm clock face away. Put your phone somewhere out of reach. Knowing it is 3.17am does not help you sleep. It measures the insomnia and adds a layer of dread to what is already difficult.

Progressive muscle relaxation — ten minutes that genuinely help. This is a technique you can do lying in bed and it works by reducing the physical arousal that keeps people awake. Start at your feet. Tense the muscles in your feet as hard as you comfortably can — scrunching your toes, tightening everything — and hold for five seconds. Then release completely and notice the difference, the sensation of relaxation, for ten seconds. Move to your calves: tense for five seconds, release, notice. Work upward through your thighs, your stomach (pulling it in tight), your hands (clenched fists), your forearms, your upper arms and shoulders (hunch them up toward your ears), and finally your face (scrunch everything — forehead, eyes, jaw). By the time you reach your face, most people are significantly more relaxed than when they started. The technique works by giving the nervous system something specific to do — the active tension and release cycle — that interrupts the spiral of anxious thought and brings attention to the body rather than the mind. It takes about ten minutes.

Get morning light as early as you can. Within an hour of waking, spend ten to fifteen minutes outside, or next to a bright window if going outside is difficult. Morning light is the most powerful signal available to your body for anchoring the circadian clock. It suppresses melatonin, confirms the start of the active day, and builds the framework on which good sleep later depends. It does not matter whether the morning is overcast — outdoor light on a grey British morning is still significantly brighter than indoor light and has the same effect. This is free, requires nothing but stepping outside, and is one of the most consistently supported interventions in sleep science.

Keep the bedroom cool. The body's core temperature needs to drop in order to initiate and maintain sleep. A room that is too warm keeps the temperature elevated and disrupts deep sleep. Around 18 degrees is optimal for most people — cooler than many bedrooms are kept.

Give the worry its own slot earlier in the evening. Take twenty minutes in the early evening — not close to bedtime — and deliberately think about whatever is worrying you. Write it down if you can. This is not about solving it. It is about giving the worry its designated space earlier in the day, so that it has less claim on the night. The thinking you do at 3am in the dark is not accurate thinking. It is louder, more frightening, and less useful than the same thinking done at seven in the evening with some light around you.

Build a wind-down in the hour before bed. The brain needs a transition between the stimulated, active state of the day and the conditions that allow sleep. Lower the lights — not just the main lights, but all of them. Reduce screen time not because of blue light myths but because screens deliver stimulating content that keeps the brain activated when you need it to be stepping back. A warm bath helps — it raises body temperature, and the drop in temperature as you cool afterwards is itself a signal to the brain that it is time to sleep. Something quiet to read. Something to listen to that requires no decisions. Whatever gives your arousal system permission to dial back gradually rather than moving from full activity to attempting sleep in a single step.

Hot flushes and night sweats — what is now available

If night sweats or hot flushes are a significant driver of your broken sleep — if you are waking drenched, or surfacing repeatedly to the sensation of heat, or finding that hormone-related symptoms are fragmenting your nights — this is a specific and treatable problem, and there are now more options than there used to be.

For people where conventional hormone replacement therapy is not appropriate — which includes many people after breast cancer and prostate cancer treatment — options were historically limited. In March 2026, NICE approved fezolinetant (brand name Veoza) for use on the NHS as a non-hormonal treatment for moderate to severe hot flushes when HRT is not suitable. It works by blocking the nerve signals in the brain that trigger the symptoms. It is not appropriate for everyone — it is not recommended for those with current breast cancer, other oestrogen-dependent cancers, or liver disease — so this is a conversation to have with your GP or oncologist about what is right for your specific situation and treatment history. But for those for whom it is appropriate, it represents a genuinely new option that did not exist until recently.

Older non-hormonal options also have good evidence behind them. Certain antidepressants — venlafaxine in particular for people taking tamoxifen, paroxetine for those who are not — have consistently shown benefit in reducing hot flush frequency and severity in cancer survivors. CBT has specific evidence for reducing the distress caused by hot flushes in people who cannot use HRT, even when it does not reduce their frequency. If hot flushes or night sweats are significantly disrupting your sleep and you have not been offered anything for them, raise this specifically with your GP. It is a treatable problem and you are entitled to options.

What to do in the next week

If you are taking sleeping tablets regularly — prescribed or over the counter — and are concerned about dependence, or find they are no longer working, please speak to your GP before stopping. Stopping some sleep medications abruptly can cause significant rebound insomnia and other withdrawal effects. Your GP can help you reduce gradually while introducing the self-help techniques in this chapter. Do not stop suddenly without support.

• The Sleep Charity National Sleep Helpline — free, trained sleep advisors: 03303 530 541, Mon/Tue/Thu evenings 7–9pm, Mon/Wed mornings 9–11am
• Macmillan Support Line — free, 8am to 8pm, seven days (can arrange booklets posted to your home): 0808 808 00 00
• Sleepstation — NHS-commissioned digital CBT-I, available in most areas, self-refer or ask your GP — sleepstation.org.uk
• NHS Talking Therapies — includes CBT for sleep and anxiety, self-refer or via GP — nhs.uk/mental-health/talking-therapies-medicine-treatments/talking-therapies-and-counselling/nhs-talking-therapies
• Macmillan on sleep problems after cancer — macmillan.org.uk/cancer-information-and-support/impacts-of-cancer/sleep-problems
• Breast Cancer Now on hot flushes and night sweats — breastcancernow.org/about-breast-cancer/treatment/hormone-endocrine-therapy/hot-flushes-and-night-sweats
• Prostate Cancer UK on hot flushes during and after hormone therapy — prostatecanceruk.org/prostate-information-and-support/living-with-prostate-cancer/how-hormone-therapy-affects-you/hot-flushes