How even one night of bad sleep can intensify the pain you feel.
It’s not uncommon to wake up aching and irritable after a poor night’s sleep.
Now, a new study from the University of California, Berkeley, published in The Journal of Neuroscience explains why.
It confirms that sleep deprivation has a direct effect on how our brains process pain, leading to more intense pain the following day.
The study sheds light on the perpetuating relationship between chronic pain and poor sleep — a vicious cycle.
“In a sense, it’s scary to see. People can be so drastically changed by losing sleep,” said lead author and UC Berkeley PhD student Adam Krause.
To research how sleep deprivation can affect pain, Krause and his team recruited 25 individuals from the undergraduate student body to undergo a pain stimulus test — once with a full night of sleep and then a week later after staying up all night.
Using a heated electrode applied to the left leg, researchers were able to gather information about pain based on the temperature applied to the skin.
In both cases the students were observed for the full overnight period, ensuring compliance in either a healthy period of sleep, or none whatsoever.
During the experiment when the subjects were sleep deprived, they reported a lower threshold for pain, meaning that patients reported feeling pain at lower temperatures than they did when well-rested.
“What was surprising to me personally was how large that effect was. Nearly 80 percent of our participants reported an increase in pain if they didn’t sleep the night before. That’s a very reliable effect,” Krause told Healthline.
Researchers also used MRI scans of the subjects’ brains to measure brain activity related to pain. What they found was surprising.
Areas of the brain associated with feelings of pain, such as the somatosensory cortex, showed increased activity after sleep deprivation. This was expected.
However, they also found that other areas — the striatum and insular cortex — that have the more complex function of classifying pain stimuli were functioning less.
“We can see that the brain, after sleep deprivation, is basically letting in more pain, but then the regions that would normally regulate or evaluate that incoming pain signal are disrupted or inhibited by sleep deprivation,” said Krause.
Fuel for the fight to end chronic pain
The study has important implications for chronic pain management as well as for better understanding how sleep impacts a person’s well-being.
“It’s nice that they were able to study this and link the idea that sleep deprivation could itself be a contributing factor to pain, and we’ve kind of known that,” said Dr. Scott Krakower, assistant unit chief, psychiatry, Zucker Hillside Hospital, Glen Oaks, New York.
Krakower is unaffiliated with the study.
Pain, mood, and other mental health problems are linked to poor sleep, but Krakower said this helps to understand why.
“We kind of already know in general, clinically, that when someone is feeling sleep deprived or having trouble with things like that, we know that they are usually, to more likely, to feel more on edge and anxious,” he said.
Particularly for those suffering from chronic pain, better understanding the role of sleep deprivation in exacerbating or mitigating pain is an important road forward. Chronic pain and sleep disorders are common comorbidities.
However, sleep disorders can often be overlooked during treatment despite the fact that treating sleep disorder concurrently has the potential to improve pain outcomes.
It’s a painful chicken-and-egg scenario in which chronic pain can disturb sleep, and restless nights lead to more pain the next day.
But there is a practical, common sense takeaway from this: Getting a good night’s rest is sound advice for chronic pain sufferers as well as the general population.
Krause and his team suggest that it’s this kind of work that reinforces the idea that sleep needs to be given more consideration as part of patient care. It may even have the potential to lower prescriptions for pain medications.
“If it is true that sleep acts like this sort of natural analgesic, that it can reduce pain sensitivity, it should be part of a broad approach to managing chronic pain. With the hope being that it will reduce our dependence on the drugs,” said Krause.
He added, “We know that these drugs tend to disrupt healthy sleep, so it may be actually that the use of these drugs for long-term pain… can actually prolong the chronic pain state.”
But, even if you aren’t dealing with chronic pain, there are plenty of reasons to focus on developing a healthy sleep schedule.
Krakower suggests that individuals struggling to get enough sleep should focus on keeping a schedule: Getting up and going to bed at the same time each day.
“If you notice that you’ve been disrupted in that routine or schedule for your day, try to get it back on track the next day. Try to remember that the next day might be better,” he said.