If you've ever struggled with falling asleep soundly, you'll know how cranky and out of sorts you feel the next day. Being deprived of sleep for a longer period of time, however, can lead to much more serious consequences, such as:
Weakened immune system
As you fall asleep, your body's immune system produces substances such as cytokines and antibodies in order to protect your body from being infected by foreign invaders such as viruses and bacteria. Certain cytokines can also aid sleep, making your immune system more efficient so that your body is protected from contracting an illness. Without a sufficient amount of sleep, your immune system is not able to build up its forces in order to protect you from infection, so your body may take longer to recover from illness. If you suffer from sleep deprivation over a long period of time, this can increase your risk of suffering from chronic conditions later in life, such as heart disease and diabetes mellitus.
Sleep can also impact the production of hormones such as ghrelin and leptin, which control your body's feelings of fullness and hunger. Leptin sends a message to your brain to let it know that you have eaten a sufficient amount, but with an inadequate amount of sleep, your brain reduces its leptin production and increases its ghrelin production, which stimulates your appetite.
Sleep deprivation can also make you feel too tired to engage in exercise, and so over time, this lack of physical activity can lead to weight gain as you're not burning a sufficient amount of calories. A lack of sleep can also lead to less insulin production and can raise your blood sugar levels.
Central nervous system disruption
Sleep plays an essential role in keeping your nervous system functioning optimally and a lack of sleep can disrupt your body's ability to process and send information. As you sleep, your nerve cells form pathways within your brain to help you retain the information you learned that day. Sleep deprivation can make it more difficult for you to learn new things or concentrate, and can also reduce your coordination.
A lack of sleep can also affect your emotional state, making you more prone to mood swings and impatience while compromising your creativity and ability to make decisions. Sleep deprivation can also worsen symptoms of depression and anxiety and can lead to impulsive behaviour, suicidal thoughts and paranoia.