Sleep and Pain

A variety of sleep disturbances, including difficulty falling asleep and frequent awakenings, are commonly reported by patients experiencing pain. Even among pain patients not reporting frequent awakening, reports of nonrefreshing sleep are common. Sleep laboratory-based studies in patients with acute pain, as well as in patients with chronic pain, show frequent arousals, difficulty falling back to sleep after nocturnal awakenings, and a reduced time spent in REM sleep.

Clearly, pain causes sleep disturbances. However, it is becoming increasingly clear that these sleep disturbances result in increased pain, thereby setting up a cycle of pain leading to disturbed sleep which, in turn, leads to more pain and then back to disturbed sleep.

In the chronic pain patient, reduced REM and disturbed deep sleep, even for 1 night can lead to increased pain.

Thus, the loss of sleep as small as one to two hours over 1 night results in a significant increase in pain. Although two hours of sleep loss for a night may not seem important, it is important to remember that the consequences of sleep loss accumulate across nights. Thus, 1-2 hours of sleep loss across 2-4 nights would be like losing an entire night of sleep.

Also, 3 to 4 awakennings lasting only 5 to 10 minutes are worse then awakening one time for 30 minutes. This is because we are probably awakening from REM sleep, and we have disturbed the stage transition. (Stage transition is what we do when we sleep and do not awaken the entire night. We cycle through sleep stages 1, 2, 3, 4 and REM four to five times per night.)

Furthermore, it may not simply be disturbed sleep that makes pain worse. The administration of narcotics and other scheduled medications, to alleviate pain may turn out to be counterproductive, as these medications are REM suppressants, and loss of REM sleep increases pain, especially muscle pain.

Another type of sleep disturbance is called Alpha/Delta Sleep. This type of sleep occurs when we are sleeping, but in pain. With Alpha/Delta sleep we do not get normal deep sleep. Alpha/Delta sleep can occur even if we do not awaken during the night.

In normal deep sleep (stages 3 & 4), our brain puts the days activities in order, resets neurotransmitters, and it is in deep and REM sleep that our muscles rebuild themselves. This does not occur properly in Alpha/Delta sleep.

We call these types of sleep disturbances "non-restorative sleep." The patient goes to bed tired and awakens tired!!

Thus, the preservation of sleep time, sleep stages, and a continuity of sleep without any awakenings are very very important parts of pain management.

For more information on sleep and breathing problems:

• See our brochure on Treatment Options for Obstructive Sleep Apnea (PDF / 8 MB)
• Academy of Dental Sleep Medicine