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Living with Insomnia: Why Do I Feel Tired But Can't Sleep?

According to research, one in four women in the U.S. struggle with insomnia compared to fewer than one in five men. Furthermore, one in every seven adults experiences chronic insomnia.

Women with insomnia often struggle with falling asleep, staying asleep throughout the night, and catching a good quality sleep. Not only does it cause excessive daytime fatigue, but it also hurts your mental health

If you've been wondering why you feel so tired lately but can't sleep, chances are you have insomnia. Below, I’ll discuss the differences between tiredness, fatigue, and sleepiness to help you understand the underlying cause of your sleeplessness. I’ll also discuss the symptoms of insomnia and the best ways to combat sleep deprivation. Let's dive in!

The Mechanism of Sleep: How Does It Work?

To understand why you can't fall asleep at night, let's discuss the intricate mechanism of sleep. We'll start by using the two laws of sleep: sleep debt and circadian rhythm, before jumping into the differences between tiredness and sleepiness. 

The Two Laws of Sleep depend on the two-process model of sleep regulation, which explains sleep duration, timing, and structure. Let's take an in-depth look:

The First Law: Sleep Debt

Sleep debt is the amount of sleep you miss during 14 days relative to the quantity your body needs. It is a function of sleep homeostasis, a complex process in which sleep pressure decreases during sleep and increases when awake.

Here's the thing: your sleep homeostasis needs to stay level. Here's what happens:

  • When you wake up, adenosine—a naturally drowsiness-inducing chemical—starts accumulating in your brain. Consequently, you experience rising sleep pressure
  • Near your bedtime, your sleep pressure hits maximum. Thus, the sleep homeostat tilts to a single side, causing sleepiness and acting as a catalyst to help you fall asleep
  • Once you catch a healthy amount of sleep, your brain flushes out the accumulated adenosine and balances the sleep homeostat

Therefore, if you don't get enough sleep, leftover adenosine causes you to feel groggy and exhausted in the morning and sleepy during the daytime. If sleep debt continues to accumulate, acute sleep deprivation transforms into chronic. 

The Second Law: Circadian Rhythm 

I know what you're thinking: if sleep pressure balances the wake time to bedtime, why don't I doze off during the day? And why do I wake up before my alarm clock goes off? 

In three words: your circadian rhythm. The circadian rhythm is your internal clock regulating sleep and wake time. Light, exceptionally bright light, kicks your brain into action by alerting circadian signals and promoting wakefulness. Additionally, natural and blue-light decreases the body's production of cortisol and serotonin, thus reducing sleepiness. 

Circadian alerting signals rise throughout the day before experiencing a temporary drop during the late afternoon. As a result, sleep pressure increases, and we feel less energetic and tired post-lunch. After the afternoon dip, the circadian rhythm counters sleepiness and hits its peak. However, your circadian alerting signals disappear when dusk falls, and your body initiates sleep.

Unfortunately, getting high-quality sleep requires your homeostasis and the biological clock's synchronization. The dynamic keeps you productive throughout the day and helps you get a good night's sleep. However, a misalignment between them can cause sleeplessness and insomnia. 

Why Can't I Sleep: The Difference between Tired, Sleepy, and Fatigued 

Most people confuse tiredness and fatigue with sleepiness. Consequently, you find yourself lying in bed at 10 p.m. staring at the ceiling, wondering why you can't fall asleep if you're so tired!

Discriminating between these three feelings can help you identify the root of sleeplessness and the cause of insomnia. Let's dive in:


Sleepiness is not feeling exhausted; it's the extreme desire to fall asleep. 

Picture this: you're sitting on a cozy, luxe sofa, your eyelids start feeling heavier, and you believe you're a second away from falling asleep. 

Typically, sleepiness builds up the longer you stay awake and relieves once you doze off. If you get the required amount of sleep, you wake up refreshed. 

Fatigue and Exhaustion

On the contrary, tiredness, fatigue, and exhaustion are sensations you feel deep within your bones and muscles. It's a heaviness that defeats you mentally and physically and makes you want to climb into bed and sleep for days. 

While fatigue occurs due to various illnesses, such as anemia or cancer, it does not result in sleep. People who feel exhausted might take a nap, but they struggle to fall asleep.


Fatigue, sleep deprivation, and mental illnesses can destroy your sleep schedule and cause fatigue. Thus, when you climb into bed, you experience sleeplessness and intense anxiety. The anxiousness, in turn, overrides the signal for sleepiness and contributes to worsening insomnia.

Contrary to popular belief, lying in bed will not help. However, the opposite might help! Staying up later and waking up at a fixed time increases your desire to fall asleep, thus improving the quality and quantity of sleep. 

What Insomnia Feels Like: Reasons You Can't Fall Asleep

Chronic insomnia can disturb your sleep cycle, making it impossible for you to get deep enough sleep and balance sleep pressure. As a result, people with insomnia often feel stressed, tired, and exhausted but unable to fall asleep. 

The American Academy of Sleep Medicine states that insomnia is considered chronic if it persists for over three months and occurs three times weekly. However, diagnosing insomnia can be tricky. It's essential to learn the underlying insomnia causes to know how it is different from fatigue:

Anxiety, Stress, and Depression

Mental illnesses like anxiety, stress, and depression can impact the quality and quantity of sleep, making it challenging to fall asleep. 

Besides this, emotional and psychological effects like worry, grief, trauma, and anger can mess up your biological clock. Treating these issues can help combat your insomnia. 

Sleep Disorders

Although insomnia is a sleep disorder, it can be a symptom of other sleep disorders like sleep apnea, restless legs syndrome, and circadian rhythm disturbances.

In people with sleep apnea, the throat and tongue muscles get too relaxed, which causes obstructions in sleep. Moreover, people with restless legs syndrome experience tingling and uncomfortable feelings in their legs, prompting them to move. 

As a result, these conditions can disrupt your sleep, which leads to daytime sleepiness and tiredness. 

Poor Habits 

Adopting poor coping habits, such as excessive alcohol consumption, drinking too much coffee, or napping late in the evening, can disrupt your sleep cycle. 

In addition, studies show that high amounts of saturated fats and carbs can increase daytime sleepiness. 

The Impacts of Insomnia- Daytime Fatigue

Sleep Foundation states that adults require at least seven to nine hours. However, research shows that 7 to 19% of adults don't get enough sleep, and up to 40% of people fall asleep during the day.

Losing sleep can increase your susceptibility to insomnia, which leads to daytime fatigue and sleeplessness. Here are several common symptoms of insomnia:

Common Symptoms of Insomnia

In insomnia, you may suffer from one or more of these symptoms:

  • Feeling fatigued
  • Inabilities to concentrate, focus, or remember 
  • Mood swings and irritability 
  • Having difficulty performing work 
  • Experiencing daytime sleepiness 
  • Experiencing tiredness and lack of motivation 
  • Making errors 
  • Feeling frustrated about your lack of sleep 

Treatment for Insomnia: Adopting Healthy Sleeping Habits

Address underlying issues such as stress, medication, and other medical conditions to restore undisturbed sleep. Combat sleep deprivation and minimize the repercussions of insomnia by learning good sleeping habits that include: 

Creating a Consistent Sleep Schedule 

Waking up simultaneously every day helps you create a consistent sleep schedule. As a consequence, sleep pressure builds up and encourages your body to fall asleep at a normal time. 

Go to Bed When You're Sleepy 

Here's the truth: lying in bed at 8 p.m. will not make you feel sleepier. You'll spend the next five hours staring at the wall, counting sheep, and wondering why you can't fall asleep! As a result, your quality and quantity of sleep will worsen. 

On the contrary, relaxing before bedtime can help you wind down and feel sleepier. 

Curate a Better Sleep Environment 

Exterior noises, bright lights, uncomfortable mattresses, and temperatures that are hot or cold are factors that can disrupt your sleep. 

Wearing earplugs, using a sound machine, experimenting with different levels of mattresses and pillows, and adding a curtain can provide the support you need to sleep better. 

Challenge Self-Defeating Thoughts

If your insomnia occurs due to stress or depression, you can learn how to sleep better with anxiety by challenging negative attitudes. 

Start by recognizing self-defeating thoughts and replacing them with realistic ones. For instance, instead of bringing yourself down by saying, "Why can't I sleep like a normal person?' try, "Lots of people struggle with sleeping problems; I just need to find the right sleeping technique." 

If none of these work, it's time for an intervention like cognitive behavioral therapy for insomnia (CBT-i) to improve sleep. Visit your doctor or talk to a sleep coach to naturally sleep better and faster for optimum health.  

The Bottom Line

Insomnia can affect your mental and emotional health, productivity, and overall physical health. Introducing healthy coping mechanisms and transforming your lifestyle can help you get high-quality sleep. 

Learn actionable strategies and coping habits to improve your sleep schedule by visiting my website. Click on the link to schedule a complimentary sleep consult with me, Morgan Adams, a certified sleep coach. Until then, sweet dreams!