In his article Chronic Pain and Insomnia: Breaking the Cycle, Dr. Deardoff states that 65% of patients who report having chronic pain also report having sleep disorders, such as disrupted or non-restorative sleep.
Do sleep disorders cause the chronic pain, or does the chronic pain cause the sleep disorders?
Research is ongoing, and there is no clear answer to the cause and effect question, but one small study suggests that frequently interrupted sleep can make one more susceptible to pain by altering the body's natural systems that regulate and control pain and can even lead to spontaneous painful symptoms.
Researchers studied 32 healthy women for seven nights. The women were assigned to one of three groups:
- a control group that slept undisturbed
- a group that was woken up eight times during the night
- a group that went to bed later than usual.
On the sixth night, the women in the latter two groups underwent 36 hours of total sleep deprivation, followed by an 11-hour recovery sleep.
During the study, researchers tested the women's pain thresholds and pain inhibition. The women in the group that had been woken up eight times during the night showed an increase in spontaneous pain, while those in the other two groups did not, showing that disrupted sleep impairs natural pain control mechanisms that are thought to play a key role in the development, maintenance, and exacerbation of chronic pain.
Conclusion: For those with chronic pain, getting continuous, undisturbed sleep is key to controlling the pain.
SOURCE: American Academy of Sleep Medicine, news release, April 1, 2007