NuroseneOct 29

The Dynamic Relationship Between Sleep and Stress

A woman with glasses sits in a coffee shop staring intently at her laptop
“It’s been keeping me up at night.”

Ever said or heard someone else say that? The relationship between sleep and stress is well known. During times of stress, our quality of sleep suffers. Poor sleep can negatively impact our stress levels and mood, which in turn makes our sleep even worse.

Repeat. Ad nauseum.

At Nurosene, we’ve found a strong correlation between those with difficulty sleeping and those with higher stress amongst users of the Nuro app. Our data shows them occurring together more often than not. These findings will help drive content and increased personalization through our Nuro app. Better understanding correlations in our data helps Nurosene to dig deeper.

Scatter graph of sleep data from Nuro app usersScatter graph of stress data from Nuro app users

But that’s not to suggest stress is necessarily a bad thing. There’s a very real evolutionary reason for it.

At its most basic, stress is our body’s response to adverse, demanding, or dangerous circumstances. It creates a state of mental, emotional, or physical strain.

  • Acute: short-lived; this is the body’s “fight or flight” response.
  • Chronic: long-term; it can have harmful effects on our mind, body, and brain.

During periods of danger — perceived or otherwise — our bodies produce large quantities of cortisol, epinephrine, and norepinephrine. These compounds trigger a physical response such as increased blood pressure and heightened muscle preparedness and we become tense and more alert to our surroundings.

This response is designed to help us stay and deal with the stressor — fight — or get away to safety as fast as possible — flight. And that had obvious benefits when we had to deal with predators and other dangers in the natural world.

Fortunately, we don’t have to confront too many saber-tooth tigers in the 21st century. In lieu of that, though, we’ve found other things to stress over, including:

  • Money
  • Work
  • Family
  • Relationships

An acute or short period of stress over a big presentation at work, for example, can actually provide the motivation and focus you need to succeed. But far too often, those short bursts of stress meant to help us pile up one upon another and we develop chronic stress.

Our fight-or-flight response is kicking in too often and for situations where neither is appropriate, such as sitting in traffic or standing in line at the bank.

The result? Many of us exist in a near-constant state of at least low-key stress.

Left untreated, that can lead to fatigue, irritability, headaches, upset stomach, hair loss, difficulty concentrating, mood swings, weight fluctuation, and more. Including difficulty sleeping.

Sleep is our body’s chance to reset, refresh, and recharge. We move through the four stages of the sleep cycle several times each night:

  • Stage 1/N1: only 1–5 minutes as we drift off to sleep.
  • Stage 2/N2: 10–60 minutes each time.
  • Stage 3/N3: (often referred to as “deep sleep”) about 20–40 minutes each time.
  • Stage 4/REM Sleep: this is when we have our most vivid dreams, lasting 10–60 minutes each time.

Experts believe that N3 is crucial for the therapeutic benefits of sleep, while REM sleep is vital for cognitive functions.

An individual suffering from chronic stress may develop insomnia, sleeping in fits and starts throughout the night and not hitting those all-important third and fourth stages.

It’s a vicious circle: stressed = poor sleep, and poor sleep = stressed. One feeds the other.

The Relationship Between Sleep and Stress

Stress begets difficulty sleeping. Difficulty sleeping begets stress. Knowing that, it stands to reason that you can improve one by improving the other.

The Impact of Sleep on Stress

A University of Pennsylvania study found that subjects limited to just 4.5 hours of sleep per night for a week reported increased feelings of anger, sadness, mental exhaustion, and yes, stress. When allowed to resume a regular sleep schedule, those same subjects reported vastly improved moods.

Periods of sleep deprivation for any reason make us more impulsive, more emotionally reactive, and more sensitive to stimuli.

A proper sleep schedule of 7–9 hours each night also allows the body to take stock and defend itself against illness or infection, which improves your chances of staying healthy. A sick body is a stressed body, both physically and mentally.

Furthermore, studies have shown that a lack of sleep activates the emotional processing and worry — aka anxiety — region of the brain. Getting a good night’s sleep can reset your system and reduce the level of anxiety and stress you’re feeling.

Sleep affects stress, and stress affects sleep.

The Impact of Stress on Sleep

As mentioned above, stress triggers the production of cortisol, a steroid hormone that stimulates vigilance and alertness as part of the fight-or-flight response. That’s (usually) good.

But consistently high cortisol levels from chronic stress can interfere with the release of melatonin, a hormone that manages the sleep-wake cycle. That’s bad. Stress can literally impair the sleep hormone.

And while quality sleep can reduce the amount of cortisol in our system, a lack of sleep itself can trigger our stress response to produce more of it.

There’s that vicious cycle again.

How to Balance the Sleep-Stress Relationship

It’s simple: get more sleep, reduce your stress.

But like most things, that’s easier said than done.

It may be impossible to remove all stress from our lives, but we can take steps to manage and control it.

In order to reduce stress and improve sleep at or near bedtime, consider:

  • Take a break to calm your mind. The 2-Minute Reset activity in the Nuro app is a wonderful way to calm your mind.
  • Breathing. Techniques like Morning or Afternoon Breathing, which can both also be found in the Recovery section of the Nuro app.
  • Turn off devices. Not only does the blue light they emit interfere with sleep signals, checking your work email before bed is going to kick your stress level up at least a few notches.
  • Avoid stimulants like caffeine and tobacco. Some studies are showing that consumption of alcohol near bedtime can interrupt Stage 4/REM sleep, have you waking frequently throughout the night, and reduce overall sleep quality.
  • Block the light. Invest in some blackout curtains. The darker it is, the better.

In general, keeping a consistent sleep schedule — going to bed and getting up at the same time throughout the week — eating healthy, and getting a little exercise each day all contribute to lower stress levels and better sleep.

New studies show that brighter days lead to better nights. The light-dark pattern during a 24-hour cycle is one of the leading cues for our circadian rhythms and biological clock.

One study found that subjects with standard windows and blinds experienced a 15-minute delay in the production of melatonin, fell asleep 22 minutes later, and woke up 16 minutes earlier than subjects with dynamic “smart” windows that allowed for more natural light during the day. The smart window subjects also saw an 11% reduction in anxiety and a 9% reduction in stress.

Additionally, we know that our mood is elevated and stress reduced when we take the time to get outside and get some sun. Win-win!

Stress can be a killer, leading to all kinds of illnesses and diseases when left unchecked. Sleep is essential for the proper maintenance of our mind, body, and brain.

The recently discovered glymphatic system in the brain is a network of vessels that helps eliminate waste and potential neurotoxins — and distribute beneficial compounds like glucose — from the central nervous system. It appears to be relatively dormant during the day and active only while we sleep.

Sleep and stress are intricately and irrevocably linked. As goes one, so goes the other, so proactive steps to improve sleep have the added benefit of reducing stress, and vice versa.