Insomnia: When to See a Doctor

What Is Insomnia and How Common Is It?

Insomnia is difficulty falling asleep, staying asleep, or waking too early, combined with daytime impairment despite adequate opportunity and circumstances for sleep. Epidemiologic estimates vary because surveys use different definitions: insomnia symptoms are common, while fewer people meet all criteria for an insomnia disorder [1].

Acute vs. Chronic Insomnia

Short-term insomnia lasts fewer than three months and often follows an identifiable stressor, medication change, travel, or acute illness. Some episodes improve when the trigger passes; others persist because sleep-related behaviors, anxiety, pain, or another disorder continues.

Chronic insomnia disorder requires more than a calendar threshold. The usual framework includes difficulty initiating or maintaining sleep despite adequate opportunity, associated daytime impairment, symptoms at least three nights per week, and duration of at least three months [2]. The distinction matters because persistent insomnia warrants a structured evaluation and treatment plan.

Who Is Most Affected?

Insomnia symptoms are reported more often by women in many population studies [1]. Sleep problems also become common during the menopause transition, especially when vasomotor symptoms are present [3]. Older adults, shift workers, and people living with mood disorders, pain, or chronic illness also have higher rates, but poor sleep should not automatically be attributed to age or hormones.

What Causes Insomnia?

The 3-P model, predisposing, precipitating, and perpetuating factors, is the most widely used conceptual framework in sleep medicine for understanding why insomnia develops and why it persists [4].

Predisposing Factors

Some people are constitutionally wired toward hyperarousal. Trait anxiety, female sex, family history of insomnia, and a tendency toward rumination all raise baseline vulnerability. Neuroimaging and polysomnographic data suggest people with chronic insomnia show higher 24-hour whole-brain metabolic rates compared with normal sleepers [5].

Precipitating Factors

A specific trigger, such as job loss, bereavement, illness, a new medication, or schedule disruption, can launch an insomnia episode. In a small randomized study, 400 mg of caffeine taken at bedtime or 3 or 6 hours beforehand significantly disrupted sleep [6]. The result supports attention to dose and timing; it does not create a universal 2 p.m. cutoff for every person.

Perpetuating Factors

These are the behaviors and beliefs that keep insomnia going long after the original trigger has passed. They include:

• Spending excessive time in bed hoping to "catch up" on sleep
• Watching the clock repeatedly during the night
• Catastrophizing thoughts such as "I will be unable to function tomorrow"
• Irregular sleep-wake schedules, including sleeping in on weekends
• Alcohol used as a sleep aid (it fragments sleep architecture in the second half of the night) [7]

CBT-I specifically targets perpetuating factors, which is why it produces more durable remission than sleep medication alone.

Medical and Psychiatric Causes

Insomnia can occur alongside another sleep, medical, psychiatric, or substance-related condition. Common contributors include:

• Obstructive sleep apnea (OSA): fragmented sleep from repeated arousal
• Restless legs syndrome (RLS): an irresistible urge to move the legs at rest
• Gastroesophageal reflux disease (GERD): nocturnal acid events that disrupt sleep
• Chronic pain syndromes: fibromyalgia, arthritis, neuropathy
• Major depressive disorder and generalized anxiety disorder
• Hyperthyroidism
• Perimenopause and menopause (declining estrogen and progesterone alter thermoregulation and sleep architecture) [3]

Treating an underlying condition may improve sleep, but insomnia sometimes requires direct treatment as well because conditioned arousal and sleep-related behaviors can persist.

When Should You Worry About Insomnia?

Poor sleep for a few nights is not a medical emergency. Several specific patterns, however, signal that a clinical evaluation should not be delayed.

The Three-Month Threshold

If sleep difficulty has lasted three months or longer and occurs at least three nights per week, chronic insomnia is possible, but the diagnosis also requires adequate sleep opportunity and meaningful daytime effects [2]. Schedule an appointment rather than assuming the duration alone confirms a disorder.

Daytime Impairment That Is Interfering With Work or Safety

Insomnia is defined not just by nighttime symptoms but by daytime consequences such as fatigue, impaired concentration, mood change, reduced performance, or errors [2]. Drowsy driving is a specific safety concern. If you are struggling to keep your eyes open, drifting from your lane, or missing parts of the drive, stop driving and arrange another way to travel [9].

Red-Flag Symptoms Requiring Prompt Evaluation

Seek evaluation without waiting three months if any of the following are present:

• A bed partner reports that you stop breathing, gasp, or snore loudly during sleep. This pattern suggests obstructive sleep apnea, which carries cardiovascular and metabolic consequences if untreated.
• You experience uncomfortable crawling sensations in your legs at rest, especially in the evening, with an irresistible urge to move them. This is the hallmark of restless legs syndrome.
• You act out vivid dreams physically, such as punching, kicking, or falling from bed. Possible REM sleep behavior disorder warrants evaluation because of injury risk and its association with neurologic disease [10].
• Insomnia began after starting or changing a medication. Corticosteroids, stimulants, some antidepressants, and other drugs can worsen sleep in some people; review timing and alternatives with the prescriber rather than stopping abruptly.
• You are experiencing suicidal thoughts, inability to stay safe, mania-like symptoms, or severe depression alongside insomnia. Seek same-day urgent help; call emergency services for immediate danger. Longitudinal studies also associate insomnia with a higher later risk of depression [11].
• Insomnia is accompanied by significant weight gain, cold intolerance, or fatigue far out of proportion to sleep loss, which may suggest hypothyroidism.
• You are pregnant and insomnia is severe, persistent, or accompanied by mood symptoms, breathing pauses, restless legs, or medication questions. CBT-I has randomized-trial evidence in prenatal insomnia and avoids exposing the fetus to a hypnotic drug [12].

A practical triage framework is:

How Is Insomnia Diagnosed?

Insomnia diagnosis is clinical. No single test confirms it, but a structured evaluation rules out competing diagnoses and guides treatment selection.

Clinical History and Sleep Diary

A clinician will ask about sleep onset latency, wake after sleep onset, early-morning awakening, total sleep time, schedule, sleep opportunity, and daytime effects. A prospective sleep diary records patterns more systematically than unaided recall, although it remains self-reported rather than objective [13].

Validated questionnaires can quantify symptoms and track change but do not replace clinical diagnosis. The Insomnia Severity Index ranges from 0 to 28 and was validated as an outcome measure for insomnia research [14].

Wrist Actigraphy

Consumer trackers can estimate patterns but are not interchangeable with clinical testing. Wrist actigraphy can help characterize sleep-wake timing over multiple days, particularly when a circadian rhythm disorder or mismatch between reported and observed schedule is suspected [30].

Polysomnography

A full in-lab sleep study is not routinely required for uncomplicated insomnia. Polysomnography is used when another disorder such as sleep apnea, periodic limb movements, parasomnia, or REM sleep behavior disorder is suspected, or when the clinical course remains unexplained [10].

Laboratory Tests

Laboratory testing should be targeted to the history and examination. Thyroid, blood-count, iron, pregnancy, or other testing may be appropriate when symptoms suggest a specific contributor. Routine estradiol or FSH testing is not required to diagnose insomnia or the menopause transition in every patient.

Evidence-Based Treatments for Insomnia

Cognitive Behavioral Therapy for Insomnia (CBT-I)

The American College of Physicians recommends CBT-I as initial treatment for adults with chronic insomnia [16], and the AASM strongly recommends multicomponent CBT-I [31]. A meta-analysis of randomized studies found improvements in sleep onset, time awake after sleep onset, total sleep time, and sleep efficiency [17]. Benefits vary, so a single remission percentage should not be promised to every patient.

CBT-I components include:

• Sleep restriction therapy: Temporarily compressing time in bed to the estimated total sleep time, building sleep drive and consolidating sleep.
• Stimulus control: Strengthening the association between bed and sleep, including leaving bed during prolonged wakefulness rather than watching a clock for a fixed minute threshold.
• Sleep hygiene education: Consistent wake time, limiting caffeine after early afternoon, reducing bright light exposure in the hour before bed.
• Cognitive restructuring: Identifying and challenging dysfunctional beliefs about sleep.
• Relaxation techniques: Progressive muscle relaxation, diaphragmatic breathing.

A large randomized trial found that digital CBT-I improved insomnia symptoms and several functional and well-being outcomes compared with sleep-hygiene education [18]. Digital programs can expand access, but that trial does not prove every program is equivalent to therapist-delivered care.

Pharmacotherapy

Medication can be considered through shared decision-making when CBT-I is unavailable, declined, or insufficient, or when short-term symptom control is needed. The AASM pharmacologic guideline makes drug-specific recommendations, most of them weak because benefits and harms vary and comparative evidence is limited [15].

FDA-approved options:

• Suvorexant (Belsomra): A dual orexin receptor antagonist studied in two 3-month randomized trials; dose choice and next-day impairment warnings come from the current label [19].
• Lemborexant (Dayvigo): Another dual orexin receptor antagonist with 12-month phase 3 efficacy and safety data [20].
• Eszopiclone (Lunesta): A nonbenzodiazepine hypnotic studied over 6 months, with adverse effects and next-day impairment still relevant [21].
• Zolpidem (Ambien): Available in immediate- and extended-release forms. The FDA label uses lower recommended initial doses for women and warns about next-morning impairment and complex sleep behaviors [22].
• Low-dose doxepin (Silenor): FDA-approved for sleep-maintenance insomnia; dosing and interactions should follow the current label and individual clinical context [15].

Benzodiazepines and nonbenzodiazepine hypnotics can cause next-day impairment, falls, dependence, or complex sleep behaviors in susceptible patients. Diphenhydramine is not recommended by the AASM for chronic insomnia [15]. Do not combine sedatives or change a prescription without reviewing other medicines, alcohol use, age, pregnancy status, breathing disorders, and driving needs.

Hormone Therapy and Insomnia

When hot flashes or night sweats drive awakenings, treating vasomotor symptoms can improve sleep. The 2022 North American Menopause Society position statement describes hormone therapy as the most effective treatment for vasomotor symptoms, while emphasizing individual benefit-risk assessment by age, time since menopause, route, dose, and contraindications [23]. Hormone therapy is not a universal insomnia drug, and CBT-I may still be appropriate.

Melatonin and Supplements

A meta-analysis of primary sleep disorders found that melatonin modestly shortened sleep latency and increased total sleep time, with effects smaller than many marketing claims imply [24]. Product quality, dose, timing, age, interactions, and the actual sleep disorder matter. Ramelteon is a prescription melatonin-receptor agonist approved for sleep-onset insomnia; suitability should be assessed rather than inferred from its mechanism.

Sleep Hygiene: What Actually Works

Sleep hygiene alone rarely resolves chronic insomnia, but specific behaviors have measurable effects on sleep physiology and support other treatments.

Light and Temperature

A small laboratory study found that light from computer monitors reduced evening melatonin in college students [25]. Screen brightness, distance, content, and timing all matter; one percentage should not be generalized to every device or person. A cool, comfortable bedroom can support sleep, but no single temperature range is medically required for everyone.

Exercise Timing

In a small randomized trial of 17 sedentary older adults with insomnia, 16 weeks of aerobic exercise improved self-reported sleep and quality of life [26]. That supports regular physical activity but does not establish one mandatory exercise schedule or bedtime cutoff.

Consistent Wake Time

A consistent morning wake time is a common CBT-I component because it helps anchor circadian timing and sleep drive. Large weekday-to-weekend schedule shifts create “social jetlag”; observational research links greater social jetlag with obesity, but it does not prove that a specific number of weekend minutes causes metabolic disease [27].

Special Populations

Older Adults

Sleep becomes lighter and more fragmented with age, but distressing or impairing insomnia is not simply “normal aging.” CBT-I has evidence in adults aged 60 and older [28]. The 2023 AGS Beers Criteria identifies benzodiazepines, nonbenzodiazepine hypnotics such as eszopiclone and zolpidem, and first-generation antihistamines as potentially inappropriate for many older adults because harms can include cognitive effects, delirium, falls, or fractures [29].

Adolescents

An adolescent who cannot fall asleep until very late but sleeps normally on a delayed schedule may have delayed sleep-wake phase disorder rather than primary insomnia. Evaluation should consider school timing, mood, substances, medications, sleep opportunity, and circadian pattern before adding a sedative.

Pregnancy

Pregnancy changes the benefit-risk calculation for every medicine and supplement. Doxylamine-pyridoxine is approved for nausea and vomiting of pregnancy, not insomnia. A randomized trial supports CBT-I for prenatal insomnia [12], making non-drug treatment an important option while obstetric and sleep clinicians evaluate symptoms and medication exposure.