What is the connection between sleep and pain?
To consider the connection, it's important to understand that complaints around sleep, by some estimates, are present in upwards of 88% of chronic pain conditions. On the opposite end of the spectrum, approximately 50% of those afflicted by insomnia report chronic pain.
Studies on the impacts of sleep deprivation have demonstrated that participants tend to develop hyperalgesia, a hypersensitivity to pain stimuli in a dose-response relationship. As the sleep deprivation progresses over many nights, the sensitivity increases. In the more specific case of conditions characterized by joint pain, those diagnosed with rheumatoid arthritis feeling a greater amount of pain following a partial sleep deprivation, not to mention the impacts it had on their fatigue levels and experience of depression.
Unfortunately, the exact mechanism for why this occurs is unclear, but researchers have a few ideas including changes in the signaling of neurotransmitters such as dopamine or opioid peptides. Another thought is the impact that sleep deprivation has on our mood and the effect that this would have on sensitizing the sleepy individual to stimuli such as joint pain.
What is the healthiest way to sleep?
It's a difficult question since there is no right answer. We all have our preferences for everything from the firmness of the bed to the pillow, to whether the window is opened or closed, and the eternal conflict about why a bed needs 10 or more decorative pillows. However, there are sleeping conditions that encourage a restful and rejuvenating snooze:
- Temperature. The optimal temperature for sleeping is anywhere from 19 - 21°C. At this temperature, our bodies create a buffer zone or microclimate of heat that surrounds the body. Research has shown that anything outside of the buffer range (31 - 35°C) can have a negative impact on the rejuvenating properties of sleep.
- Lights. Turn them off as we need the contrast between light and dark to appropriately regulate the circadian rhythms of sleep. An animal study was conducted where mice were exposed to light around the clock, and they demonstrated higher levels of depression than those with a normalized dark-light cycle. Exposure to artificial lights at night has been linked with higher risk of anything from behavioural and psychiatric disorders to breast cancer.
- Air circulation. When bedroom windows are kept shut, especially true in crisp Canadian winters, and the bedroom door is closed, levels of CO2 can swiftly rise and exceed 2500 parts per million (PPM). This reduced the quality of sleep and had impacts into the next day including feeling more uptight, tired, and sleepy. Ventilating the room improved these measures, overall quality of sleep, and even performance on a logic test.
Which position should I avoid, especially if I suffer from neck and/or back pain?
Sleeping on your front is the pinnacle of poor position. Unless you want to attempt breathing through a pillow, it forces your head and neck sideways. This extended rotation of the cervical spine can gradually contribute to misalignment as it flattens the natural curvature of the spine. Even lying on the back with a hand on the forehead recruits the scalene muscles and upper trapezius muscles and is associated with neck pain.
However, if you find that this is the only position that doesn't contribute to the pain, then consider placing a small pillow underneath the hips to elevate them off of the bed in order to align the spine.
How should we sleep with back and neck pain?
With neck and back pain, the goal is to align the spine and recruit the fewest muscles over the course of the night, leaving them relaxed and allowing you to wake up relatively pain-free. Sleeping on the side with a small pillow between the legs, or on the back with a pillow under the arch of the knees will help keep the spine aligned.
What are some ways to reduce the pain?
- Arnica montana is an herbal consideration as studies have demonstrated its topical anti-inflammatory properties. Research notes its ability to reduce the intensity of pain and improve function in those with osteoarthritis of the hands as well as an Ibuprofen Gel 5% (Optifen). Lab studies note this is due to the ability of the plant to reduce pro-inflammatory agents such as NF-ĸB via sesquiterpene lactones contained in the plant.
- It is worth your time to consider the use of acupuncture as a meta-analysis published in the Journal of the American Medical Association concluded that acupuncture has a modest, but effective ability to reduce chronic pain. Another systematic review demonstrated how acupuncture could treat insomnia, and helped augment the impacts of herbs traditionally used for sleep.
- A final consideration may be meditative movements to improve sleep quality. This includes yoga, tai chi, and qi gong which improved participant scores on a widely used measure known as the Pittsburgh sleep quality index (PSQI) when they engaged in the movements for four weeks to six months. They notice improvements in their sleep quality, how quickly they fell asleep and how long they stayed asleep. Many of these meditative practices also have benefits in reducing the sensation or experience of pain, allowing you to sleep without the distraction.