Why can’t I sleep after a cancer diagnosis? Understanding insomnia and sleep problems in cancer patients

A cancer diagnosis is life-changing — not just physically, but emotionally and psychologically too. One of the most common, yet often overlooked, side effects is disrupted sleep. Many people living with cancer experience insomnia, night waking, or poor-quality sleep, which can persist throughout treatment and into survivorship.

In fact, a recent meta-analysis of 160 studies, encompassing over 46,000 patients, found that approximately 60.7% of cancer patients experience sleep disturbances (95% CI 58.1–63.3%). This research underscores the significant impact sleep problems can have on quality of life during cancer treatment and beyond.

In this article, we explore the multifaceted relationship between cancer and sleep, how mental health factors in, and why specialised support is crucial.

Why does cancer affect sleep?

Sleep problems in cancer are complex. They often arise from a mix of physical symptoms, treatment-related side effects, and the psychological impact of facing a serious illness.

Common reasons cancer patients struggle with sleep include:

• Stress and anxiety related to diagnosis and treatment

• Pain or discomfort from the cancer or its treatment

• Side effects of medications, such as corticosteroids or hormone therapies

• Changes in daily routine due to hospital stays or altered activity levels

• Cancer-related fatigue, which can disrupt regular sleep patterns

• Fear of recurrence or disease progression, even after treatment

“When we talk about sleep issues in cancer patients, we’re not just looking at physical symptoms — we’re often seeing the psychological toll of facing a serious diagnosis. Insomnia can be both a symptom and a cause of emotional distress.”— Dr Greg Shields, Consultant Psychiatrist and Cancer Specialist Psychiatrist, Schoen Clinic Chelsea

The psychological impact of a cancer diagnosis on sleep

For many individuals, insomnia begins soon after diagnosis. The mind can race as it processes the emotional burden, treatment options, and future uncertainties. Night-time, with its quietness, often magnifies feelings of anxiety, making sleep seem even more elusive.

Over time, ongoing poor sleep can contribute to fatigue, low mood, and reduced ability to cope with daily challenges. This creates a difficult cycle where lack of sleep further intensifies emotional stress.

“We often see a cycle where people become anxious about not sleeping — and that anxiety itself makes it even harder to sleep. Addressing this early is key.”— Dr Greg Shields

Persistent sleep issues can also increase the risk of clinical depression and other mental health concerns. The effects are far-reaching, impacting overall quality of life during a challenging time.

What does the research say?

The connection between cancer, mental health, and sleep is well-established:

• A 2023 BMJ Open study found that sleep disturbances are highly prevalent among cancer patients, up to 95% in fact, and can persist well beyond the initial diagnosis, throughout treatment and even a decade into survivorship.

• Research highlights a significant relationship between emotional wellbeing and sleep quality, especially for those under the stress of a serious illness.

• Clinical evidence shows that Cognitive Behavioural Therapy for Insomnia (CBT-I) can effectively improve sleep quality among cancer patients, offering long-term benefits over purely medication-based approaches.

“CBT-I is one of the most evidence-based treatments we have for insomnia, especially in cancer patients. It helps people retrain unhelpful thoughts and behaviours around sleep — and crucially, it empowers them to take back some control.”— Dr Greg Shields

Practical strategies and innovative tools

While the strategies discussed here provide an overview of the methods we employ at Schoen Clinic Chelsea, it’s important to note that detailed, personalised advice is best obtained through a consultation. That said, here are some general approaches and innovative tools that we often discuss with our patients:

1. Prioritise high-level sleep hygiene

Instead of getting into minute details, we encourage patients to establish a consistent sleep routine and create a sleep-conducive environment. Specific tips and individual adaptations are best discussed during your consultation.

2. Leveraging technology for insights

Devices like the Apple Watch or other smart wearables can be useful for:

• Tracking your sleep schedule

• Monitoring sleep quality and disturbances

• Providing data that can help identify patterns or potential issues

These insights can be valuable for you and your healthcare team to fine-tune your sleep management strategy, however they can also become a focus of unnecessary anxiety. It’s important to use them as part of a holistic and psychologically-informed treatment plan.

3. Accessing specialist guidance

Psychological interventions like Cognitive Behavioural Therapy for Insomnia (CBT-I) are tailored to help retrain unhelpful thoughts and behaviours related to sleep. More in-depth advice on how these methods can work for you is available during a one-on-one consultation.

“The mind and body are never separate — especially in cancer. When we treat sleep problems, we’re really treating the person as a whole. Technology and personalised therapies go hand in hand in helping our patients improve their sleep and overall wellbeing.”— Dr Greg Shields

4. Connecting with our expert team

If sleep issues continue to affect your quality of life, it’s essential to speak with your healthcare provider. At Schoen Clinic Chelsea, we provide a holistic, specialist approach that includes:

• Evaluating potential medication impacts on sleep

• Supporting lifestyle adjustments and mental health therapies

• Offering referrals to targeted psychological and occupational therapy services

• As an expert in the crossover between cancer treatment and mental healthcare, Dr Shields also offers a specialised 6-week CBT-i programme to help individuals with cancer or other serious illnesses who are struggling with insomnia.

A whole-person approach to cancer care

At Schoen Clinic Chelsea, we understand that sleep is not just a symptom but a cornerstone of mental resilience, immune function, and overall recovery. Comprehensive care means addressing every facet of your wellbeing — not just the physical aspects of cancer.

“Addressing sleep isn’t about handing out a list of dos and don'ts; it’s about understanding your story and tailoring an approach that supports your overall health. That’s the essence of our holistic care.”— Dr Greg Shields

Final thoughts

Struggling with sleep after a cancer diagnosis is incredibly common, but it’s not something you have to face alone. By recognising the multiple factors at play and working closely with our specialist team, many of our patients have seen notable improvements in their sleep, mood, and overall quality of life.

If you or a loved one is experiencing ongoing sleep challenges during cancer treatment or recovery, please consider booking a consultation. Our expert team is here to help you understand and manage these complexities, using personalised strategies that encompass both mental health and physical wellness.

Interested in learning more about how we can help improve your sleep and overall wellbeing during cancer treatment?

Contact us today at Schoen Clinic Chelsea to schedule your consultation.

Reviewed by Dr Greg Shields, Consultant Psychiatrist & Cancer Specialist on 16/04/2025