Sleep is one of the most essential functions of the human body. During sleep, our body repairs itself, our brain processes information, and our overall health is maintained. But when it comes to sleep, there isn’t a one-size-fits-all approach. Some people lie awake for hours each night, unable to fall asleep, while others struggle to get out of bed even after 10 hours of sleep. So, why do some people sleep too little while others sleep too much?

Let’s explore the science and psychology behind sleep patterns and their influencing factors. It’s important to note that hypersomnia, considered the opposite of insomnia, is one of the conditions that can lead to excessive sleep, just as insomnia leads to sleep deprivation. 

The Importance of Sleep 

Before diving into why some sleep too little and others too much, it’s important to understand why sleep is crucial. Adults typically need between 7 to 9 hours of sleep per night to function optimally. Adequate sleep is vital for cognitive function, mood regulation, immune system health, and physical recovery. On the flip side, both too little and too much sleep can lead to health problems. Insufficient sleep is linked to issues like weight gain, heart disease, diabetes, and depression, while excessive sleep can increase the risk of obesity, heart disease, and even mortality. 

Why Do Some People Sleep Too Little? 

There are several reasons why some people consistently sleep too little, even when their bodies crave rest. Here are some key factors that contribute to insufficient sleep: 

1. Lifestyle Choices 

In today’s fast-paced world, many prioritize work, socializing, or other activities oversleep. Long work hours, late-night studying, or social media scrolling into the early hours can significantly reduce sleep time. This lifestyle imbalance is one of the most common reasons people get too little sleep, and it often becomes a hard habit to break. 

2. Stress and Anxiety 

Stress is a major culprit behind poor sleep patterns. When the body is under stress, it produces cortisol, the "stress hormone." High cortisol levels make it difficult for the body to relax, resulting in trouble falling asleep or staying asleep. People with anxiety or a racing mind often struggle with insomnia, which leads to them sleeping less. Over time, chronic stress can lead to severe sleep deprivation and disrupt circadian rhythms, making sleep even harder to achieve. 

3. Sleep Disorders 

Certain sleep disorders can lead to insufficient sleep. Conditions like insomnia, sleep apnea, and restless leg syndrome can disrupt the normal sleep cycle, causing individuals to wake up frequently during the night or experience poor-quality sleep. These conditions may go undiagnosed, leading to long-term sleep deprivation and health issues. 

4. Depression 

While it’s often associated with oversleeping, depression can also lead to insomnia or sleeping too little. Many people with depression find it difficult to fall asleep or stay asleep. This disruption can lead to a vicious cycle of fatigue, which exacerbates depression symptoms and makes it even harder to sleep. 

5. Genetics 

Some people are genetically predisposed to need less sleep, and researchers have found specific gene mutations that influence this amount. For example, certain individuals may function well on just 5 or 6 hours of sleep and still feel rested and alert during the day, while others require 9 hours or more to feel fully rested. 

6. Stimulants 

Caffeine, nicotine, and other stimulants are known to interfere with sleep. Drinking coffee or tea too late in the day or smoking before bed can keep you awake longer. These substances can stay in the bloodstream for hours, disrupting the body’s natural ability to wind down and fall asleep. 

Why Do Some People Sleep Too Much? 

On the other hand, some individuals struggle with sleeping too much, which can also lead to negative consequences for their health. Here's why some people may sleep excessively: 

1. Hypersomnia and Narcolepsy 

Hypersomnia, considered the opposite of insomnia, is a condition in which individuals feel excessively tired during the day and have an increased need for sleep at night. People with hypersomnia may sleep for 10 or more hours a night and still feel tired during the day. Narcolepsy is another condition in which people experience uncontrollable episodes of sleepiness and may fall asleep unexpectedly during the day, often for long periods. 

2. Depression 

Just as depression can cause insomnia, it can also cause excessive sleep. Known as "hypersomnia" in this context, depression can lead people to sleep for extended periods as they try to escape the overwhelming sadness and exhaustion they feel. The body may retreat into sleep as a coping mechanism, leading to excessive rest that worsens feelings of lethargy and emotional numbness. 

3. Chronic Fatigue Syndrome 

Chronic fatigue syndrome (CFS) is a condition characterized by severe, long-term fatigue that doesn't improve with rest. People with CFS often find themselves sleeping for long periods, only to wake up feeling unrefreshed. This excessive need for sleep can be frustrating, as the person feels their body is constantly seeking rest but never truly recovers. 

4. Sleep Apnea 

Sleep apnea, a condition in which a person’s breathing repeatedly stops and starts during sleep, can contribute to excessive sleep. While sleep apnea may cause fragmented sleep, individuals often compensate by sleeping for longer periods in an attempt to feel rested. However, this may lead to oversleeping as the body never fully enters the restorative stages of sleep. 

5. Genetics and Circadian Rhythm 

Just as some people need less sleep, others may naturally need more. Your circadian rhythm, the internal body clock that regulates sleep and wake cycles, can be genetically influenced. People with certain genetic traits may feel the need to sleep for longer periods to function optimally. Additionally, those with delayed sleep phase disorder (DSPD) may have difficulty waking up early in the morning, leading them to sleep longer at night. 

6. Substance Use or Medication 

Certain medications, such as antidepressants or sedatives, can cause drowsiness and increase the amount of sleep a person gets. Additionally, alcohol and other sedatives can disrupt the quality of sleep, causing a person to sleep longer without feeling rested. 

The Balance of Sleep 

The key takeaway is that sleep needs vary greatly from person to person. While the average adult requires about 7 to 9 hours of sleep, some may need more, while others need less. What’s most important is the quantity of sleep and quality. A good night’s sleep isn’t about the number of hours spent in bed; it’s about waking up feeling refreshed and alert, without the need for excessive amounts of sleep or the struggle to get by on too little. 

Final Thoughts 

Whether you’re sleeping too little or too much, it’s essential to recognize that both can be signs of underlying health issues. If you consistently struggle with sleep, whether it's difficulty falling asleep, staying asleep, or sleeping too much, it might be time to consult a healthcare provider. Identifying the root cause of your sleep troubles is the first step toward achieving a better, more balanced sleep schedule that supports your physical and mental well-being.

Hypersomnia is considered the opposite of insomnia and, maybe one of the conditions affecting your sleep, and seeking the right treatment can help. So, listen to your body, prioritize sleep, and take the necessary steps to ensure you get the rest you need. 

Lastly, sleep is vital to our overall health, and understanding why some people sleep too little while others sleep too much can help us take better care of ourselves.