The obvious signs of sleep deprivation are excessive sleepiness, yawning, irritability, and daytime fatigue. Stimulants like caffeine aren’t enough to override your body’s profound need for sleep. Behind the scenes, chronic sleep deprivation can interfere with your body’s inner systems and cause more than the preliminary signs listed above.
Impact on the Central Nervous System
Your central nervous system is the information highway of your body. Sleep is obligatory to keep it functioning properly; however, chronic insomnia can disrupt how your body usually sends information. Throughout sleep, pathways form between nerve cells (neurons) in your brain that help you remember new information you’ve learned.
Sleep deprivation leaves your brain exhausted, so it can’t carry out its duties as well. You may also find it more difficult to concentrate or learn new things. The signals your body sends may also come with a delay, decreasing your coordination skills and increasing your risk for accidents. Sleep deprivation also negatively impacts your mental abilities and emotional state. You may feel more impatient or prone to mood swings. It can also compromise decision-making processes and creativity.
Psychological Effects of Sleep Deprivation
If sleep deprivation continues long enough, you could start having hallucinations—seeing or hearing things that aren’t there. A lack of sleep can also trigger mania in individuals who have manic depression. Other psychological dangers include impulsive behavior, depression, paranoia, and even suicidal thoughts.
Micro sleep: A Hidden Danger
You may also end up experiencing microsleep during the day. During these episodes, you’ll fall asleep for just a few seconds or minutes without realizing it. Microsleep is out of your control and can be extremely dangerous if you’re driving. It could also make you more prone to injury due to trips and falls.
The Role of Sleep in Immune Function
While you sleep, your immune system produces protective, infection-fighting substances like cytokines. It uses these substances to fight foreign invaders such as bacteria and viruses. Cytokines also help you sleep, giving your immune system more energy to defend your body against illness.
Sleep deprivation prevents your immune system from building up its forces. If you don’t get enough sleep, your body might not be able to fend off invaders. It may also take you longer to recover from illness—long-term sleep deprivation also increases your risk for chronic illnesses like diabetes and heart disease.
Sleep and Respiratory Health
Nighttime breathing disorders affect your breathing. Obstructive sleep apnea (OSA) can interrupt your sleep and lower the quality of your breathing and sleep. As you wake up throughout the night, this can cause sleep deprivation, which leaves you more vulnerable to respiratory infections like the common cold and flu. Sleep deprivation can also make existing respiratory diseases worse, such as chronic lung illness.
Sleep Deprivation and Digestive Health
Along with eating too much and not exercising, sleep deprivation is another risk factor for becoming overweight and obese. Sleep affects the levels of two hormones, leptin, and ghrelin, which regulate feelings of hunger and fullness.
Leptin tells your brain that you’ve had enough to eat—without enough sleep, your brain reduces leptin and raises ghrelin, which is an appetite stimulant. The flux of these hormones could explain nighttime snacking or why someone might overeat later in the night. A lack of sleep can also contribute to weight gain by making you feel too tired to exercise.
Sleep’s Effect on Weight Management
Sleep deprivation also prompts your body to release higher levels of insulin after you eat—insulin controls your blood sugar level. Higher insulin levels promote fat storage and increase your risk for type 2 diabetes.
Impact of Sleep on the Cardiovascular System
Sleep affects processes that keep your heart and blood vessels healthy, including your blood sugar, blood pressure, and inflammation levels. It also plays a vital role in your body’s ability to heal and repair the blood vessels and heart.
People who don’t sleep enough are more likely to get cardiovascular disease. One analysis published in the European Journal of Preventive Oncology linked insomnia to an increased risk of heart attack and stroke.
Hormone Production and the Endocrine System
Hormone production is dependent on your sleep. For testosterone production, you need at least three hours of uninterrupted sleep, which is about the time of your first REM episode. Waking up throughout the night may affect hormone production.
This interruption can also affect growth hormone production, particularly in children and adolescents. These hormones help build muscle mass and repair cells and tissues. The pituitary gland releases growth hormones continuously. However, sleep and exercise also help induce the release of this hormone.