Stress, anger, and other heavy feelings are known to trigger the body into a fight or flight response, triggering the release of catecholamines, which include adrenaline and noradrenaline. This results in an increase in heart rate, blood pressure, and breathing rate.
Under these circumstances, falling and staying asleep becomes much harder. Furthermore, a 2018 study proved that disrupted sleep can build up more anger, which means you might get caught up in a cycle of bad sleep which leads to anger, which in turn, leads to more bad sleep.
Science has already established that the quality of sleep directly influences our overall health. One 2010 study describes sleep as ‘overnight therapy’. During sleep, and especially deep sleep stages called REM, the brain processes and stabilizes our emotions, a process that affects our mood the next day. Negative emotions trigger the release of the stress hormone cortisol, which can lead to physical and mental ailments.
In the long run, disrupted sleep can cause insomnia, depression, and even make you more vulnerable to Alzheimer’s disease.
Related: 7 Mind-Boggling Facts About the Psychology of Dreaming
As you might have gathered from the previous segments, sleep magnifies emotions and thoughts, for better or worse. Although we aren’t conscious, the brain is very active during sleep; it processes and stores new information in our long or short memory. Anger is stored in the long term memory portions of the brain.
This means a negative experience can be reduced if you stay awake after it takes place, while sleep ‘seals’ the bad emotions that stem from the experience and solidifies them. It’ll be much harder to suppress these bad memories in the future and let go of them.
