Medically reviewed by
Dacelin St Martin, MD
Triple board-certified in Sleep Medicine,
Internal Medicine, and Pediatrics.
Not getting enough sleep can affect your mood; lack of sleep can make you feel angrier and easily frustrated.
Researchers have established a bidirectional connection between mood and sleep: a negative mood can make you lose sleep, and lack of sleep can put you in a bad mood.
Further studies have been done that specifically target the relationship between sleep deprivation and anger.
Poor sleep can cause the hyperactivation of the amygdala, an increase in cortisol levels, and lower oxytocin levels which can all increase the likelihood of anger outbursts in a sleep-deprived individual.
Additionally, sleep disturbances can have a huge psychological toll on individuals that prevents them from adequately handling their emotional reactions, leading to more anger.
The Link Between Sleep And Emotions
There’s widespread interest in learning more about sleep and its role in our daily lives.
What happens when we sleep? Where do our dreams originate? Is sleep really important? How does sleep affect our daily lives?
It’s well established now that sleep deprivation can have numerous adverse effects on physical health, neurologic stability, and cognitive performance.
When you don’t get enough sleep, you are likely to feel out of energy and unable to concentrate well the next day. But what about the emotional effects of sleeplessness?
A lot of research has focused on the bidirectional relationship between emotions and sleep. We now have evidence that sleep disturbances, such as insomnia, might significantly affect our daily emotional stress and anxiety.
A good night’s sleep is critical for our daily mental functioning, and sleep deprivation can make us emotionally sensitive and vulnerable to stressful situations.
It’s now known that sleep plays a crucial role in regulating emotions, and sleep loss and insomnia intensify daily negative emotions, such as anger, confusion, and depression.
The Link Between Anger And Sleep
The average person needs around 7-8 hours of sleep every night for proper mental and physical functioning the following day.
Sleep deprivation is when a person gets inadequate sleep for several consecutive days.
There’s a well-established connection between sleep loss and mood, as sleep deprivation has been associated with anger, irritability, aggression, and a short temper.
Studies have shown that people who get a good amount of sleep each night experience fewer emotional outbursts, such as anger, than people who don’t sleep well.
In addition, clinical hypnosis has been used to help people cope with anger issues. Knowing that hypnosis is a form of sleep therapy, this further implies a relationship between sleep disturbances and anger.
The Neuroscience of Anger
Anger and aggression are evolutionary responses to potentially threatening situations.
The feeling of anger is mediated by a basic threat system in the brain that involves the amygdala, hypothalamus, and the periaqueductal gray, which are regulated by the brain’s frontal cortex.
The hyper activation of the amygdala-hypothalamus-periaqueductal gray complex can result in feelings of anger and hostility.
Moreover, high levels of cortisol, an anti-inflammatory hormone involved in the hypothalamic-pituitary-adrenal (HPA) axis, can cause increased feelings of anger and hostility.
Additionally, oxytocin, a peptide hormone, regulates social behavior, including aggression and anger.
The Neurological Effect of Sleeplessness on Anger
The amygdala plays a dual role in both emotional and fight-or-flight responses and the mechanisms of sleep.
The medial prefrontal cortex (MPFC) of the brain usually suppresses activity in the amygdala and is responsible for emotional stability.
When there is a loss of sleep, the MPFC can no longer suppress the amygdala’s activity.
This neurological response leads to the hyperactivation of the amygdala-hypothalamus-periaqueductal gray complex and consequently results in feelings of anger.
Hormonal Effect of Sleeplessness on Anger
There’s an established reciprocal relationship between sleeplessness and stress.9
People suffering from sleep deprivation experience high-stress levels throughout the day from the effort to maintain wakefulness after a sleepless night.
In response, the brain activates the hypothalamic-pituitary (HPA) axis. Consequently, the hypothalamus releases corticotropin-releasing hormone (CRH), which stimulates the release of adrenocorticotropic hormone (ACTH) from the pituitary gland.
High ACTH levels lead to an increase in cortisol levels in the blood.9 Therefore, lack of sleep can elicit an aggressive reaction by elevating cortisol hormone levels, manifesting as anger and a short temper.
Poor sleep lowers oxytocin levels and its protective effects against stress and anger. Consequently, you can feel easily irritated or agitated after a sleepless night.
The Psychological Effect of Sleeplessness on Temper
Our days are full of events and interactions that may sometimes be stressful and even annoying.
Both our bodies and minds need adequate sleep to handle everyday situations, both physically and mentally.
When you go into a deep sleep, your brain has time to declutter and unburden itself of troubling thoughts you’ve had during the day. This gives you the rest you need to be able to control your emotions and reactions the following day.
When you don’t get enough shut-eye, neither your brain nor your body gets the break it needs from a stressful day.
This result can leave you exhausted and irritable the next day and unable to rationally process events or actions that can trigger your anger.
Therefore, sleep deprivation can make you vulnerable to emotional outbursts and angry reactions to situations you would otherwise handle with more composure.
Poor sleep can interfere with your mood, efficiency, and personal relationships.
If you’re not getting enough sleep or suspect that you might have a sleep disturbance, consider going to a sleep clinic.
A sleep specialist can accurately determine why you’re having trouble sleeping and recommend a therapy plan to get you back on track.
- Patrick Y, Lee A, Raha O, et al. Effects of sleep deprivation on cognitive and physical performance in university students. Sleep Biol Rhythms. 2017;15(3):217-225. doi:10.1007/s41105-017-0099-5
- Vandekerckhove M, Wang Y lin. Emotion, emotion regulation and sleep: An intimate relationship. AIMS Neurosci. 2017;5(1):1-17. doi:10.3934/Neuroscience.2018.1.1
- Saghir Z, Syeda JN, Muhammad AS, Balla Abdalla TH. The Amygdala, Sleep Debt, Sleep Deprivation, and the Emotion of Anger: A Possible Connection? Cureus. 10(7):e2912. doi:10.7759/cureus.2912
- Sawni A, Breuner CC. Clinical Hypnosis, an Effective Mind–Body Modality for Adolescents with Behavioral and Physical Complaints. Children. 2017;4(4):19. doi:10.3390/children4040019
- Blair RJR. Considering anger from a cognitive neuroscience perspective. Wiley Interdiscip Rev Cogn Sci. 2012;3(1):65-74. doi:10.1002/wcs.154
- Leggett AN, Zarit SH, Kim K, Almeida DM, Klein LC. Depressive Mood, Anger, and Daily Cortisol of Caregivers on High- and Low-Stress Days. J Gerontol B Psychol Sci Soc Sci. 2015;70(6):820-829. doi:10.1093/geronb/gbu070
- Fekete EM, Seay J, Antoni MH, et al. Oxytocin, Social Support and Sleep Quality In Low Income Minority Women Living with HIV. Behav Sleep Med. 2014;12(3):207-221. doi:10.1080/15402002.2013.791297
- Vaeroy H, Schneider F, Fetissov SO. Neurobiology of Aggressive Behavior—Role of Autoantibodies Reactive With Stress-Related Peptide Hormones. Front Psychiatry. 2019;10:872. doi:10.3389/fpsyt.2019.00872
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- Colten HR, Altevogt BM, Research I of M (US) C on SM and. Extent and Health Consequences of Chronic Sleep Loss and Sleep Disorders. National Academies Press (US); 2006. Accessed June 23, 2022. https://www.ncbi.nlm.nih.gov/books/NBK19961/