The Bidirectional Relationship Between Sleep and Stress

Sleep is an amazing biological imperative. It’s a time when everything in the human body resets.

Everything in our physiology calms down. The heart rate slows, blood pressure lowers, and tissue repairs.

It’s also the time for us to process the events and emotions we experienced throughout the day. Sleep allows us to heal and reset, not just physically and mentally, but emotionally as well.

The emotional reset is vital. When we don’t get enough sleep, we struggle to manage stress, and higher levels of stress can affect the quality and duration of sleep. There is a bidirectional relationship between sleep and stress.

How Much Sleep Do We Need?

The recommended amount of sleep is a moving target. Years ago, eight hours was the recommendation for adults. But now six is the recommended minimum. It’s almost as if there’s been an adjustment for the system. People are overworked and getting around six hours – often less – of sleep per night. So, the recommendation of eight hours decreased.

Despite what some daily recommendations might say, six hours or less is not enough sleep for most people. It’s not deprivation, but we aren’t giving the mind and body enough time to reset. Over long periods, insufficient sleep can contribute to a plethora of health challenges.

There is also a correlation between lack of sleep and diabetes, cardiovascular issues, and the immune system. When we sleep, our heart rate slows. The decreased rate allows blood pressure to go down and the cardiovascular system, as a whole, to get a respite. For this reason, sleep is essential for our cardiovascular health. The heart is a muscle, and like all muscles, it needs a chance to recuperate and repair after working hard.

Sleep also reduces stress on the insulin system. Studies now show that otherwise, healthy adults are more prone to present with insulin resistance.[1]

Stress and sleep are tightly interwoven. A poor night of sleep leaves people feeling grouchy, but it also impacts memory, acuity, and judgment, all of which can contribute to emotional stress at low levels.

The Relationship Between Sleep and Stress

We know that emotional or psychological stress can adversely impact our quality of sleep, but it’s a bit hard to quantify.

Caffeine and environmental factors like blue-light are easy to study and measure. Emotional stress levels, however, are subjective, and physicians and scientists have to rely on what the patients in the studies report.

There is a lot of research on severe stress, like PTSD, and how it affects sleep, but most of us are dealing with a continuous, low level of emotional stress like family, work, and bills. We know that it affects sleep quality because of patient reports; it’s just harder to measure than extreme stress.

When we look at the physiological markers of people diagnosed with insomnia – using EEGs, blood tests, and HPA axis markers – we see states of hyperarousal day and night. The stress experienced throughout the day is transferring over to the night on a physiological level.

In less severe circumstances, the simple fact that you’re having trouble sleeping can compound itself into more stress, making it even more challenging to fall asleep. For example, you can’t sleep, so you might start stressing out about how tired you’re going to be in the morning and how that work project might play out with you struggling with fatigue, irritability, and lack of focus.

Stress doesn’t have to be negative, though. Any time your adrenal glands activate for cortisol use, it’s considered stress. An excellent example of this is a productive day at work. You powered through, stayed late, and got a ton accomplished. You feel great, but now you can’t sleep because you’re wired. You’re body and mind are still in full-on flight-flight mode, and it’s impacting your ability to rest. Your body is having difficulty transitioning sympathetic (arousal mode) to parasympathetic (rest and digest mode). When stuck in that in-between state, it doesn’t matter whether or not your experiences were positive or negative – our physiology handles it the same.

How to Improve the Sleep-Stress Cycle

According to the American Psychological Association, only 20% of Americans report having excellent sleep quality. Forty-two percent say their sleep is fair to poor, and 43 percent report stress keeps them awake at night. An even more alarming statistic says 37 percent of adults say they are fatigued because of stress, and adults who sleep fewer than eight hours per night report higher stress levels than those who get a full eight hours of rest.

The average American sleeps less than seven hours per night. So, first, we need to address the fact that six hours is not enough. The goal should be eight hours of quality rest per night.

But how do you get eight hours of sleep? Since the relationship between sleep and stress is bidirectional, which should we focus on when our minds are in a tailspin?

You can attack sleep and stress simultaneously by creating a routine and practicing some basic sleep hygiene. Just like we create bedtime routines for children to help them transfer from sympathetic to parasympathetic, adults can do the same. Going to bed at the same time every night —even on the weekends— is critical for correcting a poor sleep-stress cycle. Keeping the bedroom as dark as possible when it’s time for bed is essential as well. Avoid screens for at least an hour before bedtime because the blue-light simulates sunlight and messes up our pineal gland’s ability to regulate the release of melatonin, which prepares our body for sleep.

Related Content: Common Sleep Problems in Children and Tactics to Help

Similar to screens, try not to eat directly before bed. Give your body a couple of hours to digest your dinner. The same goes for caffeine and alcohol; your body needs ample time to process those chemicals out of your system. If not, they can drastically impact your sleep quality and start the stress cycle over.

Deep breathing exercises or meditation before bed can also help to relieve stress and ‘calm the nerves.’ Our brains seek resolution. Sleep helps us with this as it consolidates memories and assimilates the emotions and experiences of the day. But we can improve this process with some basic reflection, especially when we’re feeling stressed out. Reflecting upon the things that increased our stress levels and reminding ourselves that it’s over now and tomorrow is a new day can help alleviate the much of stress that keeps us awake at night. We can take that a step further by thinking positive thoughts for each of the day’s emotional stressors.

Exercise is beneficial for eliminating stress and regulating the body’s systems. Not only is it fantastic for helping to correct problems associated with sleep and stress, but it’s vital for our overall wellbeing. Just be careful not to exercise too late, so your body has time to wind down.

The bidirectional relationship between sleep and stress is complex and challenging to measure because everyone reacts to emotional stress differently. We all have different baselines for how much sleep for optimal mental and physical operation. Both long-term stress and lack of sleep can have serious physiological consequences, so make sure to implement a nightly routine, a well-balanced diet, and regular exercise to help correct your sleep cycle. If you feel like your sleep-stress cycle is spiraling out of control, contact your functional medical practitioner for a consultation as soon as possible.

By Dr. Stephanie O'Niell, DC, DICCP

*These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure or prevent any disease.

[1] "Sleep Duration as a Risk Factor for Diabetes ... - NCBI - NIH." https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2276127/. Accessed 16 Apr. 2020.