Difficulty sleeping is a common source of frustration that I often hear from patients. While pain often causes insomnia, studies suggest that the reverse may be true as well – not enough sleep can lead to more pain. In fact, some researchers now believe that a good night’s rest can serve as a powerful pain reliever.
There seems to be a correlation between how well we sleep on any given night, and how sensitive we are to experiencing pain the next day. Consider a Norwegian study that found that insomniacs were more likely to pull their hands out of a bucket of ice-cold water sooner than those without sleep problems, suggesting an increased sensitivity to pain. The less sleep they got, the quicker they pulled their hands out. The most striking finding was that those who had insomnia and chronic pain were more than twice as likely to yank their hands out of the cold water early.
Studies have also shown that sleep deprivation can cause significant changes in pain thresholds, and even suggest that the same stimulus can feel painful to a sleep-deprived individual but not to someone who had a good night’s rest. A recent study from UC Berkeley looked at brain activity of sleep-deprived participants experiencing pain to learn more about the sleep-pain connection, and they came across a few interesting findings. They saw an increase in activity in an area of the brain known as the somatosensory cortex, where sensations throughout the body are processed and pain sensitivity can be increased. But they also found that a lack of sleep impairs the brain’s natural pain-relieving circuits found in reward pathways and feedback loops, which rely on dopamine, our feel-good neurotransmitter.
Daytime fatigue – that feeling of sluggishness and low energy that hits the day after a bad night’s sleep – may also cause a greater sensitivity to pain. Harvard researchers looked at pain sensitivity in sleep-deprived mice and found that they could improve the mice’s pain by increasing their daytime alertness by giving them caffeine. In fact, the study authors reported that doing so worked better than giving the mice morphine!
It’s good to know that getting better sleep can help reduce pain, but what if pain is the thing that’s keeping you from getting to sleep in the first place? At my pain management center, we try a few different approaches that can help break the pain-insomnia cycle, including providing special classes devoted to sleep, where we review common sleep mistakes and how to best remedy them. A movement specialist, like a physical therapist, can sometimes help with sleep positioning or work on parts of the body that seem to get the most activated when trying to sleep. For example, padding around an elbow or wrist can alleviate pressure points if nerves in that area are prone to getting irritated when lying down. We also talk about habits that boost the odds of sleep, like avoiding caffeine after noontime and dimming or turning off lights an hour before bedtime.
My behavioral health team is also well-versed in cognitive-behavioral therapy (CBT) for sleep. CBT is a form of talk therapy that involves working with a trained therapist to zero in on the thoughts and behaviors that interfere with sleep and then develop strategies to eliminate them. Research suggests that CBT may be a more effective tool than any other form of treatment for sleep disorders. Even though CBT treatment may not directly eliminate the underlying pain, studies show that it can still help improve sleep patterns, even with chronic pain.