Poor sleep and chronic pain often occur together, but research suggests the relationship goes deeper than simply being uncomfortable at night. Sleep and pain influence one another through shared brain and nervous system pathways, creating a cycle that can be reinforced by our thoughts and behaviors. Evidence suggests that poor sleep may actually have a stronger effect on pain than pain has on sleep.
How Common Are Sleep Problems in People With Chronic Pain?
Sleep problems are extremely common among people living with chronic pain.
- Between 67% and 88% of people with chronic pain report sleep problems.
- 44% meet criteria for a diagnosable sleep disorder.
- The two most common sleep disorders in chronic pain populations are insomnia and sleep apnea.
- More than 50% of people with insomnia also have chronic pain.
Sleep difficulties can affect physical health, emotional well-being, productivity, and healthcare costs. They are also linked to depression, anxiety, lower physical activity, and weakened immune function.
Can Poor Sleep Make Pain Worse?
One reason is that sleep affects the brain's ability to regulate pain.
The brain normally uses a process called top-down inhibition to turn down the volume of pain signals. After a poor night's sleep, this pain-control system becomes less effective, making pain feel more intense.
Poor sleep also:
- Increases inflammation.
- Slows healing by reducing deep sleep.
- Disrupts important brain chemicals such as serotonin and epinephrine, which help regulate mood, stress, and pain.
- Increases emotional distress and worry, which can further amplify pain sensitivity.
Can One Night of Poor Sleep Increase Pain?
Research suggests that even one night of sleep deprivation can increase pain sensitivity. People who were awakened multiple times during the night also reported greater sensitivity to pain than people whose sleep remained uninterrupted.
Researchers have even found that significant sleep deprivation can make strong pain medications feel less effective.
How Does Pain Disrupt Sleep?
Pain creates a state of physical and mental alertness that makes sleep harder.
People with pain often experience:
- Difficulty falling asleep.
- More frequent awakenings.
- Less deep sleep.
- Increased focus on pain sensations at night.
- Worry about symptoms and the next day, which keeps the brain alert.
Research shows that people who worry more about their pain often report both higher pain levels and poorer sleep.
What Happens in the Brain When Sleep and Pain Interact?
A key connection involves the autonomic nervous system, which controls automatic functions such as heart rate, breathing, digestion, and blood pressure.
The system has two branches:
- The sympathetic nervous system, often called the "fight-or-flight" system.
- The parasympathetic nervous system, responsible for rest, recovery, and repair.
During healthy sleep, the parasympathetic system takes over, allowing the body to repair tissues, clear waste from the brain, and process pain signals more effectively. When sleep is repeatedly disrupted, the sympathetic system can remain activated, keeping the body in a state of stress and increasing pain sensitivity.
What Happens During a Normal Night of Sleep?
Sleep cycles through several stages.
A typical cycle lasts about 90 minutes, and most people experience four to five cycles per night. The first half of the night contains more deep sleep, while the second half contains more REM sleep, the stage associated with dreaming.
Is It Normal to Wake Up During the Night?
One surprising fact: waking up briefly during the night is normal. Most people wake up 6 to 12 times per night, but the awakenings are usually so short they are forgotten by morning. For people with chronic pain, however, these awakenings often become longer and more disruptive.
Does Sleep Change With Age?
As people age, sleep naturally becomes lighter and more fragmented. Older adults spend less time in both deep sleep and REM sleep, which can make sleep feel less refreshing.
Two sleep disorders become particularly common:
Insomnia
- Affects more than 50% of older adults.
- Is associated with worse physical health, emotional distress, and greater pain.
Sleep Apnea
- Affects approximately 30% to 50% of older adults.
- Common signs include loud snoring, gasping during sleep, and persistent daytime fatigue even after a full night's sleep.
- Untreated sleep apnea is associated with hypertension, heart disease, diabetes, and increased mortality risk.
How Can We Improve Sleep?
There are helpful strategies to optimize your sleep. Sleep is regulated by three key systems: sleep drive, circadian rhythm, and arousal system. Supporting each of these systems can help improve sleep quality over time.
- Sleep drive is your body's natural pressure to sleep. The longer you're awake, the sleepier you naturally become. But when you nap for too long, spend extra time in bed, or aren't very active during the day, that sleep pressure may not build up as strongly by bedtime.
- Circadian rhythm is your body's internal clock that helps regulate when you feel awake and when you feel sleepy. A regular sleep-wake schedule, morning sunlight, and less bright light at night can help keep this rhythm in sync.
- The arousal system refers to how alert or activated the brain and body are. Chronic pain, stress, worry, and frustration about sleep can keep the nervous system on high alert, making it harder to fall asleep or stay asleep. Reducing worry and helping your mind and body unwind before bed can help calm this stress response.
Can Improving Sleep Reduce Chronic Pain?
Yes. Research increasingly shows that sleep is not just a victim of chronic pain—it is often a driver of it. Poor sleep increases pain sensitivity, weakens the body's natural pain-control systems, and keeps the nervous system in a heightened state of stress. Because of this, improving sleep may be one of the most effective ways to reduce pain, improve daily functioning, and support long-term health.
