What lack of sleep does to your body + [Download FREE Workbook]

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Your body needs sleep as much as it needs food and air to function at its best. If you have ever spent a night tossing in bed unable to get the rest you require to recover, you know you wake up cranky. We can often catch ourselves saying, that “Hey, I feel tired because I didn’t have a good night sleep”. But, the lack of sleep goes way beyond just feeling cranky or unproductive, the long-term effects of sleep deprivation can lead to many severe concerns.

Science has linked poor sleep quality to various health problems such as weak immune system, stress, memory loss, and other related problems. Before we unleash what lack of sleep does to you and your physical health, let’s understand what sleep is and how we really fall asleep.


lack of sleep

Sleep, what is it?

We spend one-third of our lives sleeping, but we all have a very vague idea about what sleep is. Given the fact that we are not even aware when we are asleep, this concept remains like a mysterious chapter of our lives. We may think that nothing happens when we are sleeping, but actually the opposite is true in reality. Our brains and body are much more active during sleep than when we are awake.

Sleep scientists have been exploring “sleep” in depth from many centuries, and they define it in terms of its characteristics and behaviors. When we sleep, we usually have brain patterns and physiological functions that change. Sleep happens in two main categories which are further sub-divided into three other stages. And how good or bad we sleep depends on the stages and transitions in the sleep cycles. In the next section, we will define these stages and their specific purposes.

Sleep architecture, how we sleep?

Sleep has a structure, it is an active process for both our mind and body to rest and recover. We can divide sleep stages in broadly two parts: REM and non-REM or commonly known as NREM sleep. REM is rapid eye movement sleep and NREM is non-rapid eye movement sleep. NREM is further divided into three phases. Let’s look at them in detail below:

NREM Stage 1: This early transitional stage is also known as N1 sleep which can last for 5-10 minutes. It’s a stage between wakefulness and sleep, you shift in and out of consciousness. It’s easy to wake you up during this stage, you may not be even aware that you are sleeping. When you’re in stage 1 sleep, alpha waves are dominant in your brain.

NREM Stage 2: Stage 2 is a phase of light sleep. You will spend 50 percent of your time in this particular stage. During this stage, your body is relaxed, breathing rate decreases, and heart rate drops down leading you to enjoy sound rest and preparing your body for deep sleep. At this stage, your brain waves shift to theta waves.

NREM Stage 3 and 4: Deep sleep or slow wave sleep occurs in this stage. It is characterized by presence of delta waves. This is the stage when your brain deeply descends into unconsciousness. During this particular stage, your body releases a growth hormone into the bloodstream which helps your body to recover. Stage 3 is a critical time for your body to restoring strength and functioning to tissues, muscles and your overall body.

REM: Rapid eye movement is the sleep stage when we dream. You reach REM sleep just after 90 minutes into the night. During REM sleep, your brain increases its activity in comparison to other stages. REM sleep is an essential phase of sleep for learning and memory, a time when the brain processes and stores information. Whenever you wake with an awareness of dreaming, you likely awoke from REM sleep.

Sleep Cycles: So, we do not just experience one round of normal sleep cycle which is transitioning from N1, N2, N3, N4 and REM sleep at night. Instead, we have several of these cycles which phase in and out based on different factors. Factors such as age, lifestyle habits, environmental factors or health quality affect our overall sleep architecture. They all impact how we sleep and how much sleep do we need which changes over time. An average adult requires 7-8 hours of sleep in general, and inadequate sleep is associated with numerous health problems.

Dangers of not sleeping well

The healthy sleep occurs with 4-5 sleep cycles over night including all the different stages of sleep. Our bodies need optimal sleep for proper functioning. Many researches have concluded that sleep deprivation can lead to physical, emotional and physiological damage.

In extreme situations, it can also lead to death.

An ongoing lack of sleep has been closely linked with hypertension, heart attacks, diabetes, obesity, depression, decreased brain function, memory loss, weakened immune system, lower fertility rates, and psychiatric disorders. Here are five main dangers of lack of sleep:

Sleep and Memory:

Sleep plays a very critical role in learning and thinking. One night of unrestful sleep can lead to inattentiveness, lack of focus, short temper, and fatigue in general. But did you know that sleep is essential for memory consolidation? During the night, various sleep cycles play an important role in “consolidating” memories in mind. Whatever information you have been exposed to during the day gets in your short term memory, but you need a good night sleep to let that data transfer into your long term memory.

Studies have revealed that lack of sleep interferes with the rhythm of neuronal firing in a region of the hippocampus called CA1 which is the brain structure responsible for the formation of long-term memories.  Ever heard of the phrase sleep on the problem? The saying came into being because sleep helps you process information and put it on the “right shelf”.

Sleep and Alzheimer’s

One of the most important discoveries in the last few years is that the brain clears out toxins much more rapidly when we are asleep than when we are awake. Alzheimer disease is the most common form of dementia leading to memory loss and other sorts of cognitive problems that can hamper your daily routine. Scientists suggest that there are several types of protein deposits (Beta-amyloid proteins, Tau proteins) that cause the degradation of brain cell, memory loss, learning and mood problems; symptoms which are related to the disease. Poor quality of sleep is linked to building up of these toxic proteins in the brain. In fact, Alzheimer and Sleep Deprivation form a feedback loop, one influencing another.

Sleep and Immune System

Lack of sleep depresses your immune system. When you sleep, your immune system releases proteins called cytokines. Cytokines help promote good sleep and recovery. When you get sick, or you have infection or inflammation, your body requires more cytokines for recovery. But, lack of sleep can decrease the production of these beneficial proteins. Besides, your body’s ability to produce fighting antibodies and cells is also reduced when you don’t sleep properly. To stay healthy, during the flu season, it is highly recommended to get proper sleep of 7-8 hours on top of other strategies improving the immune system.

Sleep and Depression

Depression and sleep problems often go hand-in-hand. On a regular day, lack of sleep can cause you to be irritable and cranky. However, when you are sleep deprived over a more extended period, it can lead to depression and anxiety. In fact, lack of sleep is one of the main critical symptoms of clinical depression. 75% depressed patients report significant increase in sleep problems such as inability to fall asleep, or short duration of sleep.

It’s important to note that  lack of sleep will not itself cause depression, but it does play a crucial role. Insomnia and depression feed on each other. But, here is a silver lining, treating sleep issues can help reducing depression and anxiety. To maintain a healthy mental balance and keep your stress levels under control, quality night sleep is of utmost importance.

Sleep and weight gain

Sleep is nutrition for the brain, too little sleep can trigger a stress hormone called cortisol in your body. Cortisol is an inflammatory hormone that keeps you awake and regulates your appetite. When you are unable to sleep, a hormone called Ghrelin also spikes up which triggers feelings of hunger. As a result, people who are unable to fall asleep, constantly feel stressed and hungry despite eating adequately.

Lack of sleep also worsens your food making decisions. According to a study published in the Nature Communications, a single night of sleep deprivation is enough to impair your frontal lobe that controls these decisions. You crave more sugar and carbohydrate-rich foods. Eventually, you eat more, you do not eat right, and hurt your waistline.


Sleep is very crucial for good health and longevity. Your brain is able to forge a new connection and retain memory with high-quality sleep that transitions through different stages. Sleep deprivation can exhaust your mind, decrease your coordination skills, affect your emotional health, increase your risk of chronic illnesses, contribute to weight gain, and overall negatively impact your work and life. Therefore, one must understand the importance of good night rest and use effective methods to enhance sleep without medication. To know how you can begin creating a downtime routine and improve sleep, download this free workbook 7 days to a better sleep

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