How Stress Affects Sleep

One of the fundamental ways for the body to revitalise itself is to get enough sleep. But some people suffer from lack of sleep. Sleep deprivation is becoming a common condition in modern societies and has been affecting mood and performance. Inside your body, there’s a stress hormone that can play a major role in robbing you a good night’s sleep – cortisol.

The Importance of Sleep

Sleep plays a vital role in good health and well-being. Getting enough quality sleep can have beneficial effects on your physical health, mental health, quality of life and safety. It is not simply “switching off” your body. It is essential, not only for humans but for almost all animals.


The hazard from insufficient sleep can occur in an instant (such as motor accidents), or can occur over time. For instance, chronic sleep deprivation can increase your risk for some long-term health problems. It also can affect how well you think, react, work, learn and interact with others.

What Happens During Sleep

75% of our sleep at night goes through non-rapid eye movement (NREM) sleep. As we begin to fall asleep, we enter NREM sleep, which has 3 stages:

Stage 1

You’re between being awake and falling asleep. Sleep is still shallow.

Stage 2

Sleep starts to become deep. You’re about to become unconscious from surroundings. Your respiratory and heart rates are regular. The temperature of your body decreases.

Stage 3

This is the phase where you’re at deepest and most restorative sleep. Your blood pressure decreases. Breathing becomes slower. Your muscles are relaxed. There is an increase of blood supply to the muscles. The tissues grow and repair themselves. Energy is restored. Hormones are produced including growth hormones that help with growth and development.


The other 25% of our sleep at night goes through rapid eye movement (REM) sleep. The first REM takes place about 90 minutes after falling asleep and recurs about every 90 minutes, getting longer later in the night.


In REM sleep, just as the name implies, your eyes are rapidly moving, darting back and forth. Also, REM sleep provides energy to the brain and the body and supports daytime performance. Dreams occur in this phase as your brain is getting active. Your muscles are turned off, thus your body becomes immobile and relaxed.


Cortisol levels dip at the time you go to bed and goes up through the night to promote alertness in morning.

The Price of Chronic Sleep Deprivation

If you’ve been sleeping less than the standard 8 hours a night in a long term, you’re bound to suffer from its side effects such as headaches, irritability, frequent infections, anxiety, depression, confusion, and generalized physical and mental fatigue.


Not only insufficient sleep can make you feel crappy. Studies show that even mild sleep deprivation can destroy your health over time and increase your risk of getting diabetes, obesity and breast cancer.


Stressful situations cause your cortisol levels to rise. Therefore, any stressful events happened in the late afternoon to early evening will make it difficult for you to relax and fall asleep in the night. Also, one of the many effects of cortisol is to increase your alertness, which you should be avoiding right before you go to bed.


Cortisol levels normally peak in the early morning as a way to get you moving and face the challenges of the day. But later, cortisol levels will begin to drop and continue to decrease gradually throughout the day. This is where we start to feel sluggish, and by noon, we feel the afternoon slump. This is your body’s way of telling you that the day is almost over and you have to get ready to sleep.


However, instead of getting ready for sleep, modern lifestyle cause most of us to do things to keep ourselves awake in the evening so we can get evening activities done. For example, going to a business dinner, attend a party or spend time with the family.


Such lifestyle provides less time for our cortisol levels to fully dissipate. The result – our bodies aren’t fully recovered and repaired from the damaging effects of chronic stress. You wake up feeling groggy.

How to Get a Good Night’s Sleep

Here are some ways to achieve quality sleep:

  • Maintain a regular sleep/wake schedule
  • Steer clear of caffeine 4 to 6 hours before bedtime
  • Don’t smoke, especially before bedtime or if you’re awake at night
  • Avoid alcohol and heavy meals before sleep
  • Exercise regularly
  • Make your room comfortable
  • Try waking up on time without using an alarm clock


Sleep is our ultimate energiser. A complete sound sleep is important to keep ourselves functioning healthy. If your body is asking for it, don’t deprive yourself of some zzzs. Nothing’s more refreshing than getting enough sleep and waking up refreshed.