Anyone living with long-term pain knows how hard it can be to fall asleep at night. The NHS says so directly: many people with long-term pain find it difficult to sleep at night — and sleep deprivation can also make pain worse. (NHS — 10 ways to reduce pain) The NHS also lists long-term pain among the things that keep you from a good night's sleep. (NHS — Insomnia)
This text explains what we know about the link between sleep and pain. It is not a pain-treatment guide and does not replace a doctor.
A two-way street
An expert review by Haack and colleagues (2019) summarises that pain can be both a cause and a consequence of sleep deficiency. Pain disrupts sleep; short or disturbed sleep in turn lowers pain thresholds and can increase pain that comes on by itself (for example muscle pain or headache). (Haack et al. 2019 — PMC)
According to the same review, population studies show that poor sleep quality and insufficient sleep duration are risk factors for developing chronic pain. That is an association in populations, not a prediction for individuals. In people with chronic pain, a vicious cycle can develop: a bad night enhances pain, which in turn disturbs sleep. (Haack et al. 2019 — PMC)
What an experiment showed
A study by Krause and colleagues (2019) brought 25 healthy adults aged 18–30 into the lab. After one night without sleep, their pain threshold to heat dropped — they rated a lower temperature as painful than after a normal night. Brain scans showed an amplified response in the area that detects pain and a blunted response in areas that evaluate it. (Krause et al. 2019 — PMC)
A second part of the study followed 236 people online over two nights and two days while they slept as usual. Even ordinary night-to-night changes in sleep quality were linked to changes in pain the next day. (Krause et al. 2019 — PMC)
Limits: the lab part involved young healthy people, one sleepless night and heat-induced pain — not patients with chronic pain.
Why it might happen
The Haack review describes how sleep deficiency affects several systems that influence how pain is processed — including the body's own pain relief (the opioid system) and immune and hormonal pathways. According to the review, short-term sleep disruption in healthy people impaired this built-in pain inhibition. The authors also acknowledge that very little is known about the basic mechanisms behind the relationship. (Haack et al. 2019 — PMC)
What it means for ordinary days
- The NHS advises people with long-term pain to keep a normal sleep routine: go to bed at the same time, get up at a regular time and avoid daytime naps. (NHS — 10 ways to reduce pain)
- For insomnia as a disorder, the review says cognitive behavioural therapy for insomnia (CBT-I) is the first-line treatment; it has also been shown to work in people who have both chronic pain and insomnia. (Haack et al. 2019 — PMC)
- According to the review, some painkillers (for example opioids) can have both sedative and sleep-disrupting effects. (Haack et al. 2019 — PMC) If you feel your medicines are spoiling your nights, talk to your doctor — don't change the dose on your own.
When to see a doctor
- If sleep problems persist, the NHS advises seeing a GP. (NHS — 10 ways to reduce pain)
- Likewise if you have had trouble sleeping for months or it is affecting your day — a GP may offer CBT. (NHS — Insomnia)
- This article does not address the causes of pain. Have new, severe or worsening pain assessed by a doctor.
- An AI health check is not a medical review. This article is not medical advice.
Takeaways
- Pain and sleep affect each other in both directions.
- One sleepless night lowered the pain threshold in healthy volunteers.
- The mechanisms are not known in detail.
- A regular routine helps; for insomnia, CBT-I is the first choice.
- Don't change painkillers or treatment without a doctor.
Sleep will not cure pain. But when the night improves, the day has a little more in reserve.
Our sources
Research and further reading. Practical suggestions are editorial ideas, not a personalised treatment plan.
