Insomnia - Causes, Types & Treatment That Works

Insomnia is the most common sleep disorder and one of the most undertreated. Sleeping pills manage the symptom. CBT-I and root-cause care address why you cannot sleep in the first place, and the evidence shows that distinction matters.

DEFINITION

What is Insomnia?

Insomnia is persistent difficulty falling asleep, staying asleep, or waking too early, despite having adequate opportunity and desire to sleep. Chronic insomnia is defined as occurring at least three nights per week for three months or longer.[1] It is the most common sleep disorder, affecting an estimated 10 to 30 percent of adults in the United States.[2]

Unlike occasional sleepless nights, which are a normal part of life, chronic insomnia becomes self-perpetuating. The longer it continues, the more the brain learns to associate the bed with wakefulness and anxiety about sleep, creating a cycle that medication alone cannot break.

At Rebis Health, we treat insomnia as a whole-person condition. The question is never just "how do we get you to sleep tonight?" It is "why is your brain not letting you sleep, and what needs to change so that it can?"

10-30% of US adults experience chronic insomnia[2]
6-10% worldwide prevalence of insomnia disorder[3]
#1 CBT-I is the first-line recommended treatment, above sleep medication[4]

TWO PRESENTATIONS

Types of Insomnia

Insomnia presents in different ways depending on where in the sleep cycle the difficulty occurs. Understanding the type helps identify which contributing factors are most likely driving it.

Difficulty falling asleep

Sleep Onset Insomnia

Difficulty falling asleep at the beginning of the night, typically taking more than 30 minutes to fall asleep despite trying. Most commonly associated with anxiety, hyperarousal, irregular sleep schedules, or circadian misalignment. The brain is too activated to transition into sleep.

Difficulty staying asleep

Sleep Maintenance Insomnia

Waking during the night or too early in the morning and being unable to return to sleep. Often associated with stress hormones, hormonal fluctuations during perimenopause or menopause, depression, chronic pain, or underlying sleep-disordered breathing that is fragmenting sleep from below the surface.

ROOT CAUSES

What Causes Insomnia?

Insomnia is almost never caused by a single factor. At its core, most chronic insomnia involves a state of hyperarousal, where the brain and nervous system remain overactivated at night. Understanding what is driving that hyperarousal is the key to treating it.

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Hyperarousal and the Learned Insomnia Cycle

Insomnia patients experience increased metabolic rate, body temperature, heart rate, and elevated levels of stress hormones at night.[5] Even when the original stressor resolves, the brain has learned to associate the bed with wakefulness and anxiety. This self-perpetuating cycle is the reason CBT-I, not medication, is the recommended first-line treatment.

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Anxiety, Stress, and Mental Health

  • Anxiety is the most common psychological driver of sleep onset insomnia
  • Depression is strongly associated with early morning awakening and sleep maintenance insomnia
  • Chronic stress elevates cortisol and keeps the nervous system activated into the night
  • Insomnia and mental health conditions are bidirectionally linked, each worsening the other
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Hormonal and Metabolic Factors

  • Perimenopause and menopause are among the most common causes of new-onset insomnia in women over 40, driven by declining estrogen and progesterone
  • Cortisol dysregulation disrupts the natural nighttime drop in arousal needed for sleep
  • Thyroid dysfunction, particularly hyperthyroidism, causes physiological hyperarousal
  • Blood sugar instability can trigger nighttime waking, particularly around 3 AM

Behavioral and Environmental Factors

  • Irregular sleep schedules weaken the circadian signal that drives sleep pressure
  • Caffeine use too late in the day delays sleep onset and reduces deep sleep
  • Alcohol disrupts sleep architecture even when it helps with initial sleep onset
  • Screen use and light exposure at night suppress melatonin and delay the circadian clock
  • Spending too much time in bed awake teaches the brain that bed is a place for wakefulness
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Medical Conditions and Medications

  • Chronic pain conditions disrupt sleep maintenance throughout the night
  • Undiagnosed or untreated sleep apnea causes arousals that present as insomnia
  • Restless leg syndrome and periodic limb movements fragment sleep at night
  • Certain medications, including some antidepressants, steroids, and decongestants, can cause insomnia as a side effect

SIGNS TO WATCH

Insomnia Symptoms

Insomnia produces both nighttime sleep difficulties and daytime consequences. The daytime symptoms are often what drive patients to seek help, but they are directly caused by the nighttime sleep disruption.

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Nighttime Symptoms

Taking more than 30 minutes to fall asleep most nights
Waking one or more times during the night
Waking too early and being unable to return to sleep
Racing thoughts or anxiety at bedtime
Watching the clock and feeling anxious about sleep
Feeling unrested even after a full night in bed
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Daytime Consequences

Fatigue and low energy that does not resolve with rest
Difficulty concentrating, memory problems, or brain fog
Irritability, mood changes, or emotional dysregulation
Anxiety about sleep and increased dread of bedtime
Reduced work or social performance
Reliance on sleep medication, alcohol, or supplements to sleep

WHY IT MATTERS

How Chronic Insomnia Affects Health

Chronic insomnia is not just a quality of life issue. Research consistently shows it has downstream effects across every major body system.

Mental Health and Mood

Insomnia significantly increases the risk of developing depression and anxiety disorders, and makes existing mental health conditions harder to treat. The relationship is bidirectional and self-reinforcing, with poor sleep worsening mental health and mental health disruption worsening sleep.[6]

Cardiovascular and Metabolic Health

Chronic insomnia is associated with elevated blood pressure, increased cardiovascular disease risk, impaired glucose regulation, and higher rates of metabolic syndrome. Elevated nighttime cortisol and chronic sympathetic nervous system activation are the primary drivers of these effects.

Immune Function

Deep sleep is when the immune system performs its most critical maintenance work. Chronic insomnia impairs immune surveillance, reduces vaccine response, and increases susceptibility to infection. Stress hormones elevated by insomnia suppress immune function directly.

Cognitive Function and Brain Health

Sleep is when the brain clears metabolic waste products through the glymphatic system, consolidates memories, and processes emotional experience. Chronic insomnia impairs all of these processes, with accumulating evidence linking long-term sleep disruption to increased dementia risk over time.

THE GOLD STANDARD

What Is CBT-I and Why Does It Work?

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CBT-I outperforms sleep medication for long-term insomnia treatment

The American College of Physicians recommends Cognitive Behavioral Therapy for Insomnia (CBT-I) as the first-line treatment for chronic insomnia, above sleep medication. Unlike medication, CBT-I addresses the underlying cause and produces durable improvements that last beyond the treatment period.

CBT-I is a structured program that identifies and changes the thoughts, behaviors, and sleep habits that perpetuate insomnia. It is not simply "good sleep hygiene advice." It is an evidence-based clinical intervention with a robust body of research behind it.

The core components include sleep restriction therapy, which temporarily limits time in bed to build homeostatic sleep drive; stimulus control therapy, which reestablishes the association between bed and sleep; cognitive restructuring, which targets the catastrophic thinking about sleep that maintains hyperarousal; and relaxation and mindfulness techniques to reduce physiological arousal at bedtime.

Research shows CBT-I produces statistically significant improvements in sleep onset latency, wake after sleep onset, total sleep time, and sleep efficiency, with effects that are maintained at follow-up after treatment ends, unlike sleep medication whose benefits stop when the prescription stops.[3]

COMPREHENSIVE CARE

Insomnia Treatment at Rebis Health

At Rebis Health, insomnia treatment begins with understanding why a specific patient cannot sleep, not with a prescription. Our multidisciplinary team evaluates the full picture, addresses contributing factors from multiple angles, and delivers CBT-I alongside medical and functional medicine care.

1

Comprehensive Insomnia Evaluation

Every patient receives a thorough sleep history, review of medical comorbidities, medications, hormones, lifestyle factors, and mental health contributors. We use the evidence-based Five Finger Approach to ensure all relevant domains are evaluated before treatment begins.

2

Cognitive Behavioral Therapy for Insomnia (CBT-I)

Our behavioral sleep medicine specialists deliver CBT-I as the primary treatment for chronic insomnia. This includes sleep restriction therapy, stimulus control, cognitive restructuring, sleep hygiene individualized to the patient's specific pattern, and relaxation techniques to reduce nighttime arousal.

3

Ruling Out and Treating Underlying Sleep Disorders

Undiagnosed sleep apnea and restless leg syndrome frequently present as insomnia. Our team evaluates for and treats these conditions when present, because treating insomnia alone will not restore sleep if an underlying breathing disorder is fragmenting it from below the surface.

4

Hormonal and Functional Medicine Evaluation

Our functional medicine team evaluates cortisol rhythms, sex hormones, thyroid function, blood sugar regulation, and nutrient status for factors driving nighttime hyperarousal. For perimenopausal and menopausal women in particular, this evaluation often reveals the primary driver of insomnia that behavioral therapy alone cannot fully address.

5

Circadian Rhythm and Light Optimization

For patients with circadian misalignment driving sleep onset difficulties, personalized light therapy protocols and circadian alignment strategies can shift the biological clock to better match desired sleep timing, improving both sleep onset and morning alertness.

6

Medication Management When Appropriate

When medication is indicated, either as a short-term bridge during CBT-I or as an adjunct for comorbid conditions, our board-certified sleep physicians prescribe and monitor medications as part of a comprehensive plan. We work toward reducing medication dependence, not increasing it.

Frequently Asked Questions: Insomnia

Sources

  1. MedlinePlus. Insomnia. National Library of Medicine. medlineplus.gov
  2. Non-pharmacological treatments for insomnia: a focus on components of CBT-I. Kosin Medical Journal 2024. kosinmedj.org
  3. Steinmetz L et al. Network meta-analysis examining efficacy of components of cognitive behavioural therapy for insomnia. Clinical Psychology Review 2024. sciencedirect.com
  4. American College of Physicians. Management of Chronic Insomnia Disorder in Adults. acpjournals.org
  5. Insomnia disorder: hyperarousal and clinical features. Cambridge CNS Spectrums. cambridge.org
  6. Effects of CBT on sleep quality in women with menopausal insomnia: a systematic review and meta-analysis. PMC 2025. ncbi.nlm.nih.gov/pmc