Sleep and Stress Part 1: How Exactly Does Stress Interfere With Sleep?
It is 'common sense' in a way that it does - but how exactly does stress interfere with sleep?
Meet Linda. Linda works in a big, bustling, and vibrant retail business. She loves that her work helps people feel great about themselves. It's gratifying for her, and she finds it fun.
A common scenario
However, Linda doesn't make much money, and she is having relationship struggles that seem to affect everything in the home. To earn a bit more money, and to have a bit of time away from it all, she's taken a second part-time job which isn't appealing but is a bit of money.
Though working two jobs has benefitted Linda financially, she now allows herself no time to do things for herself at all. She's given up her workouts and walks because she doesn't feel she should take that time because she has less time in general outside of work. She has also traded her usual evening hot bath and a book for doing housework and other domestic chores. Linda is also grumpy and easily upset, and she has started to toss and turn at night.
Even though she likes what she does, Linda is exhausted after her very long days. Still, instead of sleeping, she has started to lay in bed thinking about her relationship, work issues, and her financial situation. Linda is spending time mulling over options and scenarios in her mind while laying in bed, but not getting anywhere with settling on a solution. She is growing increasingly anxious, and so she tosses and turns with worry, gets a bit of sleep, and eventually gets herself up for another long day. She repeats this night after night now.
Stress happens to everyone
This kind of scenario is nearly universal to one degree or another. Negative stress happens to everyone at some point and can cause everyone temporary sleeping trouble. That sleeping trouble doesn't always turn into insomnia, though it represents one of its most common causes.
But how does this kind of stress cause us so much trouble with sleep?
The effects of stress on our bodies
Stress creates a biochemical cascade of hormones in the body through the activation of something called the HPA Axis.1
These hormones help prepare our brains, eyes, and muscles to act quickly in the face of danger. Adrenalin helps our heart pump more strongly and more efficiently, getting blood to where it needs to be to fuel physical action. Glucocorticoids are complex chemicals that prime the 'energy systems' of the body for a quick response. Other chemicals help us focus our minds on problems - ideally to help solve them. But when we are anxious and not thinking clearly due to a lack of sleep, this focus can be a double-edged sword; we focus on the negative instead of on solutions.1
Cortisol is one hormone involved in the fight or flight response system. Cortisol also plays a critical role in the circadian rhythm - the cycle regulates the timing of natural waking and sleeping. Typical amounts of cortisol help play a part in the 'scheduling' of when we wake up in the morning and when we get sleepy in the evening. Cortisol levels are at the lowest point in the late evening (encouraging us to be sleepy) and start to increase from 2, or 3 am until we wake up.1
The effects of stress on our sleep
When we are anxious, especially in the evening, it becomes a challenge for this natural fall in cortisol to occur. Our bodies need this drop in cortisol to fall asleep, so this high level is a problem for the natural rhythm of sleep. Then, if this hormone level is too high or stays high, it can keep us awake until that 2 or 3 am time when it starts to cycle back toward a higher level through the day. That's one reason people sometimes describe a particular time as a 'window' for sleep, and if they stay up too late, it's hard to fall asleep. Cortisol is just one reason that happens.
So, returning to Linda: when Linda is in bed and thinking about the things she is trying to sort out in her life, she is experiencing higher than usual stress and anxiety. She is also experiencing these increases in adrenaline and cortisol that make sleep challenging during this stressful time.
Can you relate?
This kind of sleeplessness happens to everyone at some point in their lives. For some, it passes when the stress passes. For some, though, it sets up a cycle where insomnia can develop. Check out part 2 for more on how stress can cause insomnia.
Do you recognise the start of your sleeping trouble with a stressful situation?
Does anyone else in your family have insomnia?