Insomnia
Table of contents
Having a few nights of poor sleep is a common experience. Insomnia becomes clinically significant when difficulty sleeping persists despite having sufficient time and suitable conditions for rest, and begins to affect energy levels, concentration, mood or daily activities.
What is insomnia?
Insomnia is a sleep disorder characterised by a persistent difficulty in falling asleep, staying asleep throughout the night or sleeping until the desired time. Some people take a long time to fall asleep; others wake up repeatedly or remain awake for long periods during the night. They may also wake up too early and be unable to get back to sleep.
The number of hours slept provides information, but does not in itself define the disorder. Sleep requirements vary from person to person and change with age. What is truly characteristic is that there is difficulty sleeping when there is a suitable opportunity to do so, and that this disturbance has consequences during the day.
This latter aspect helps to distinguish insomnia from getting little sleep for other reasons. A person who voluntarily reduces their hours of rest due to work, leisure or family responsibilities may experience sleep deprivation, but generally retains the ability to sleep when they have the time. In insomnia, however, sleep remains difficult even when conditions are favourable.
When symptoms occur on at least three nights a week, persist for three months or more and have a significant impact during the day, the condition is usually considered a chronic insomnia disorder. These criteria form part of the diagnostic approach set out in the .
The amount of sleep required varies from person to person. To diagnose insomnia, the main factors considered are whether there is persistent difficulty sleeping when the opportunity arises, and how this difficulty affects the person during the day.
Would you like more information about insomnia?
Understanding how sleep works and what factors can disrupt it helps you to distinguish between an occasional episode and a persistent problem, and to find out about the options available for dealing with it.
Symptoms of insomnia
Night-time symptoms can take various forms. Difficulty falling asleep is one of the best-known symptoms, but insomnia can also manifest as frequent awakenings, prolonged periods of wakefulness during the night, or waking up too early when you still want to sleep. These symptoms can occur in combination and vary over time.
Normal sleep is not entirely continuous either. Throughout the night we go through different cycles and may experience brief awakenings, many of which are so short that we do not even remember them the next day. In insomnia, these periods of wakefulness become significant due to their duration, frequency or the difficulty in getting back to sleep.
The daytime consequences form a central part of the disorder. Fatigue, lack of energy, irritability, difficulty concentrating, reduced mental alertness, memory problems or a decline in usual performance may occur. Some people describe the feeling of needing to make a greater effort to carry out tasks that they previously performed with ease.
Intense drowsiness is not always present. In fact, a characteristic feature of insomnia is feeling very tired and, despite this, continuing to have difficulty falling asleep. This phenomenon is linked to a state of hyperarousal, a term describing the sustained, excessive activity of the brain and bodily mechanisms that promote alertness.
When the problem persists, sleep itself can also become a source of alertness. Calculating how many hours remain before getting up, repeatedly checking the clock or anticipating the consequences of a bad night’s sleep increases the attention focused on sleep and can make it even more difficult for sleep to occur spontaneously.
Causes and risk factors for insomnia
Insomnia usually arises from the interaction between a specific individual predisposition, one or more factors that initially disrupt sleep, and mechanisms that may perpetuate the problem over time.
Some people’s sleep is more vulnerable to stress, changes in routine or certain life events. This predisposition can be triggered by a specific event: an illness, pain, a complex situation at work or within the family, bereavement, intense worry, hormonal changes, a hospital admission, a journey or any circumstance capable of temporarily disrupting sleep.
In many cases, sleep gradually returns to its usual pattern once that situation has passed. In others, behaviours begin to emerge that are intended to compensate for poor nights’ sleep but end up disrupting sleep regulation even further. Going to bed much earlier, getting up later, lying awake in bed for long periods, taking prolonged naps or constantly changing sleep schedules can disrupt the regularity of the sleep-wake cycle.
Growing anxiety about not sleeping can add another mechanism that perpetuates the problem. After several difficult weeks, it is understandable to anticipate another bad night’s sleep or to fear being unable to function the following day. The bedroom may thus begin to be associated with effort, frustration and wakefulness rather than with rest.
This process explains why insomnia that began during a period of stress can persist even after that situation has been resolved. The initial trigger and the factors that maintain the disorder need not necessarily be the same.
Medical conditions, mental health problems, certain medicines and substances may also play a part. Caffeine and nicotine promote wakefulness; alcohol may initially induce drowsiness, but tends to fragment sleep later on. Assessing these factors forms part of a comprehensive clinical evaluation.
Diagnosis of insomnia
Diagnosis begins by accurately piecing together how the person sleeps and how they feel during the day. The medical history helps to establish when the problem first arose, how often it occurs, approximately how long it takes to fall asleep, what the awakenings are like, and what impact all of this has on daily life.
This initial assessment also covers sleep schedules on weekdays and at weekends, whether the person takes naps, sleep-related habits, and consumption of caffeine, alcohol or nicotine, as well as any medication being taken. Medical and emotional history helps to identify factors that may be interfering with sleep or conditions that require a parallel assessment.
The next step is usually to observe sleep patterns over several days. A sleep diary is frequently used for this purpose, in which the approximate times of going to bed and waking up, the time taken to fall asleep, night-time awakenings and naps are recorded. The aim is not to measure every minute precisely, but to reveal patterns that are difficult to discern by recalling individual nights.
Validated clinical questionnaires may also be used. One of the best known is the Insomnia Severity Index (ISI), a brief scale that helps to assess the severity of symptoms and the impact of the problem, as well as facilitating comparison during follow-up.
When actigraphy provides useful information
When sleep schedules are highly variable or there is a suspicion that the problem may be related to the biological clock, actigraphy may be used. This test involves a small device, usually worn on the wrist, which records activity and rest over several days and allows the sleep-wake pattern in daily life to be studied.
Its main purpose is to answer specific questions, such as determining whether there is a highly irregular sleep schedule or a possible disruption to the circadian rhythm. The current European guidelines specifically identify actigraphy as a supportive tool in selected situations, rather than as the primary test for diagnosing insomnia.
When might a polysomnography be carried out?
If the medical history reveals loud snoring, breathing pauses, abnormal movements during sleep, unexplained daytime sleepiness or other signs of a different disorder, it may be necessary to carry out an objective assessment of sleep.
Polysomnography records variables such as brain activity, breathing, oxygenation, heart rate and body movements over the course of one night. It is particularly valuable when sleep-related breathing disorders, periodic limb movements or other abnormalities are suspected, and may also be considered in certain cases of insomnia that do not respond to the expected treatment.
The diagnostic process is therefore built up progressively: first, the clinical pattern is understood; then, tools are added that can answer specific questions.
The medical history and sleep diary provide an insight into the pattern of insomnia. Actigraphy helps to analyse sleep schedules and rhythms, whilst polysomnography is used when it is necessary to investigate other disorders or certain more complex situations.
What other conditions can disrupt sleep
It is important to distinguish insomnia from other disorders because various conditions can produce seemingly similar symptoms and, on occasion, co-exist in the same person.
Circadian rhythm disorders occur when the body’s internal clock is out of sync with the social timetable. A person with phase delay, for example, may find it extremely difficult to fall asleep at a conventional time, yet sleep well if they can go to bed and get up several hours later.
Obstructive sleep apnoea can repeatedly disrupt sleep through breathing pauses. Loud snoring, episodes of apnoea observed by another person, waking up feeling as though one is suffocating, or marked daytime sleepiness can help guide the diagnosis.
Restless legs syndrome causes an uncontrollable urge to move the legs, often accompanied by unpleasant sensations that occur at rest and tend to intensify in the afternoon or evening. This condition can make it considerably difficult to fall asleep.
Parasomnias, certain movement disorders, hypersomnias and other sleep disorders may also form part of the differential diagnosis. The purpose of a specialist assessment is not simply to confirm that a person is sleeping poorly, but to determine what is actually disrupting their sleep.
Treatment of insomnia
Treatment aims to restore sufficiently uninterrupted and restorative sleep, reduce the impact of the disorder during the day and address the factors contributing to its persistence. The strategy is tailored to the duration of the problem, sleep characteristics, associated medical conditions and the treatments each person is already using.
When insomnia has recently begun as a result of an identifiable situation, addressing the trigger and maintaining a stable sleep pattern can aid recovery. In chronic insomnia, the approach must also address the mechanisms that have become independent of the initial cause.
Cognitive Behavioural Therapy for Insomnia
Cognitive behavioural therapy for insomnia (CBT-I) is currently the treatment of first choice for chronic insomnia in adults, including those with other associated medical conditions. This is established by the .
CBT-I is a structured intervention and goes far beyond providing general recommendations on sleep hygiene. One of its components, stimulus control, aims to re-establish the bed as being primarily associated with sleep, particularly when, after months of insomnia, it has come to be linked with long periods of wakefulness and worry.
Another component temporarily adjusts the time spent in bed to the amount of time actually spent asleep. Although it may seem counterintuitive, lying in bed for many hours trying to catch up on sleep often increases the time spent awake and further fragments sleep. The aim of this strategy is to initially concentrate sleep and gradually extend the time spent in bed as the continuity of sleep improves.
The therapy also addresses the expectations and thoughts that increase wakefulness: anticipating that a bad night’s sleep will make it impossible to function the following day, constantly checking the time, or interpreting every time you wake up as a sign of failure. This can be complemented by relaxation techniques, education on how sleep works, and personalised advice on schedules, exercise, light, caffeine, alcohol or naps.
Habits that promote sleep
Regular sleep-wake patterns, adequate exposure to light during the day, physical activity, a comfortable sleeping environment and caffeine intake that does not interfere with rest all help to maintain good sleep regulation.
These measures are particularly valuable as part of a broader strategy. In cases of established chronic insomnia, treatment also targets the specific mechanisms that perpetuate sleep difficulties – something that general sleep hygiene recommendations do not always achieve on their own.
Pharmacological treatment
Medications may be introduced when the clinical situation warrants it. The choice of medication takes into account age, other medical conditions, the pattern of insomnia, concomitant treatments and the expected duration of the intervention.
Benzodiazepines and so-called Z-drugs can facilitate the onset or maintenance of sleep and are mainly used for limited periods. Close monitoring is important because some of these treatments may lead to tolerance, dependence, residual drowsiness, cognitive impairment or an increased risk of falls, particularly in older people.
In certain situations, other medicines with a sedative effect may be considered, always after assessing their indication and potential adverse effects. The fact that a medicine causes drowsiness does not necessarily mean that it is an appropriate treatment for every type of insomnia.
Orexin receptor antagonists constitute a distinct therapeutic class. Orexin is a chemical signal in the brain that helps maintain wakefulness; these medicines reduce this activating signal. In Spain, the AEMPS considers daridorexant to be an option for patients with moderate-to-severe chronic insomnia who require pharmacological treatment, whilst CBT-I remains the first-line treatment wherever it is available.
Melatonin
Melatonin is a hormone involved in synchronising the biological clock and signalling the night-time period. For this reason, its function differs from that of a conventional hypnotic, and its usefulness depends on the type of sleep problem, age, time of administration and formulation.
The European guidelines recommend extended-release melatonin for limited periods in people aged 55 or over with certain forms of insomnia. This is distinct from assuming that any melatonin preparation is suitable for any sleep difficulty.
Course and prognosis of insomnia
Insomnia may last for a few days or weeks, occur in episodes or become persistent. Its progression depends both on the factors that triggered it and on the mechanisms that have subsequently developed.
An episode linked to stress, illness or a major life change may resolve once the situation stabilises. When it has been present for months or years, there are usually additional factors — disrupted sleep schedules, increased arousal, the association between bed and wakefulness, or anticipatory worry — which can be specifically addressed.
The chronic nature of the disorder does not mean it is irreversible. CBT-I can bring about lasting improvements because it addresses these maintenance mechanisms rather than merely inducing sleep on an ad hoc basis.
It is also important to understand that recovery is not measured by achieving identical nights’ sleep. Normal sleep fluctuates and may temporarily worsen during periods of stress, travel, illness or changes to routine. A favourable outcome means that these fluctuations no longer trigger the onset of new, prolonged periods of worry and difficulty sleeping.
Preventing insomnia and reducing the risk of it becoming chronic
Not all episodes of insomnia can be prevented, particularly when they are associated with illnesses, life events or significant changes. It is, however, possible to help ensure that a temporary sleep disturbance returns to its usual pattern and to reduce certain factors that contribute to its persistence.
Maintaining a relatively consistent wake-up time, staying physically active and ensuring exposure to daylight during the day, and avoiding systematically trying to make up for a bad night’s sleep with major changes to one’s schedule all help to preserve the body’s natural sleep regulation.
It is also helpful to take a flexible approach to normal variations in sleep. After a difficult night, spending excessive time in bed or starting to monitor every aspect of sleep can actually increase alertness at precisely the time when the body needs to regain its natural rhythm.
When difficulties recur over several weeks or begin to affect day-to-day life, an early assessment can help identify which mechanisms are emerging and prevent certain compensatory strategies from becoming entrenched.
Specialists who treat insomnia
The course of treatment depends on the cause of the sleep problem. The first aim is to determine whether there is an insomnia disorder, a disturbance of the sleep-wake cycle, another sleep disorder, or a medical or emotional condition that is interfering with sleep.
At the Publio Cordón Memorial Hospital, the Neurological Sleep Disorders Unit is the specialist centre for the assessment of chronic insomnia, daytime sleepiness, circadian rhythm disorders and other neurological sleep disorders. The assessment begins with a detailed medical history and may include sleep diaries, actigraphy, polysomnography or other tests where specifically indicated.
Where severe snoring, breathing pauses, waking with a feeling of suffocation or oxygenation problems are predominant, the Respiratory Sleep Medicine Unit may become involved to investigate obstructive apnoea, hypoventilation and other nocturnal respiratory disorders using respiratory polygraphy or polysomnography, and to determine the appropriate treatment.
If the problem is related to upper airway obstruction, certain nasal or anatomical abnormalities may require the involvement of the Department of Otorhinolaryngology and the Snoring and Sleep Apnoea Unit, which forms part of that speciality. In selected cases, the assessment of facial or mandibular anatomy may also require the collaboration of Oral and Maxillofacial Surgery.
Where anxiety, depression, bipolar disorder or other emotional problems play a significant role, Psychiatry may be involved in the process. Their involvement enables an assessment of the extent to which the emotional disorder is contributing to insomnia and allows for the coordination of psychological and pharmacological treatment where indicated.
Hormonal and metabolic disorders can also affect sleep. Endocrinology and Nutrition may be involved where there are thyroid disorders, obesity, metabolic disorders or other endocrine problems affecting sleep. In women with insomnia associated with hot flushes, night sweats or other symptoms of perimenopause or menopause, gynaecology can provide a specific assessment of the hormonal context.
In other situations, additional specialities may be involved. Persistent pain, certain neurological conditions, cardiovascular problems or complex pharmacological treatments can alter sleep patterns and require a coordinated approach with the relevant departments.
The team therefore adapts to the cause and complexity of the problem. Not everyone with insomnia requires the same tests or needs to be assessed by all these specialists: the aim of the care pathway is to identify which aspect of sleep is disrupted and to refer each case to the team that can provide the most benefit.
Living with insomnia
When insomnia persists, sleeping can cease to be an automatic process and instead become a task that takes up an ever-increasing amount of space in daily life. It is common to anticipate how the night will go, to rearrange activities for fear of tiredness, or to constantly try to make up for what are considered lost hours.
A key part of treatment involves gradually reducing this sense of struggle. The aim is not to monitor every minute of sleep or to chase a ‘perfect’ figure, but to regain a sufficiently stable sleep pattern so that it no longer dictates the decisions you make the following day.
Smartwatches and apps can provide estimates of sleep schedules, physical activity and certain physiological variables, but their data should be interpreted with caution. The European guidelines themselves point out that commercial devices have not been shown to be sufficiently capable of diagnosing insomnia and may, in some people, increase anxiety about sleep figures.
Maintaining an active lifestyle and sticking to reasonably consistent sleep schedules is usually more helpful than overhauling your entire routine in response to every bad night’s sleep. Recommendations should, however, be tailored to each individual and should not become new, rigid rules that increase the pressure surrounding sleep.
It is also worth accepting that even after a clear improvement, there may still be some worse nights. Sleep is affected by stress, illness, travel and changes to one’s routine. Learning to interpret these fluctuations as part of normal variability, rather than as the inevitable start of a relapse, can help to sustain long-term recovery.
Preguntas frecuentes
How many hours of sleep are needed for sleep to be considered normal?
There is no one-size-fits-all figure. Sleep requirements vary from person to person and throughout life. A diagnosis of insomnia is based on persistent difficulty sleeping when there is ample opportunity to do so, and on the impact this has during the day – not solely on the number of hours slept.
Is it normal to wake up several times during the night?
Normal sleep involves brief awakenings between its various cycles, many of which go unnoticed. They become significant when they are frequent or prolonged, make it difficult to get back to sleep, and ultimately affect rest or daytime functioning.
Is a polysomnography test necessary to diagnose insomnia?
Diagnosis usually begins with the patient’s medical history, sleep patterns and tools such as a sleep diary. Polysomnography is used when there are symptoms suggesting other disorders, such as apnoea or periodic limb movements during sleep, or in certain cases with a complex clinical course.
Is melatonin effective for all types of insomnia?
Its effectiveness depends on the type of problem, age, formulation and time of administration. Melatonin plays a key role in regulating the body’s internal clock, which is why different sleep disorders may respond differently.
Which specialist treats insomnia?
It depends on the patient’s condition. A unit specialising in sleep disorders can carry out the initial assessment and decide whether further tests are required or whether consultation with neurology, respiratory medicine, psychiatry or other specialities is needed. The course of treatment is tailored to the patient’s symptoms and any associated conditions.
Can insomnia that has been going on for years be improved?
Yes. The fact that the problem has persisted does not mean it is irreversible. In chronic insomnia, mechanisms may have become established that perpetuate the difficulty in sleeping, and specific treatments such as cognitive behavioural therapy for insomnia enable us to target precisely these mechanisms.
Medical information for general guidance
This information is intended to help you understand what insomnia is, how it can become chronic, what information is gathered during your assessment, and what the main treatment options are. Sleep is a complex process, and the same difficulty in getting a good night’s sleep can have different causes; therefore, an individual diagnosis depends on the pattern of symptoms, their progression and each person’s circumstances.
At the Publio Cordón Memorial Hospital, we believe it is important for medical information to be accurate, understandable and useful in guiding each person through their care journey. Our specialists devote part of their work to explaining conditions, tests and treatment options in an accessible way, helping patients and their families to better understand each stage and to participate with greater confidence in decisions about their health. This commitment to knowledge and public outreach is also part of our dedication to research and scientific dissemination.
When sleep difficulties persist, have a significant impact during the day or are accompanied by breathing pauses, severe drowsiness, abnormal movements or other symptoms, a medical assessment can determine what is disrupting sleep and which approach is most appropriate. Drowsiness that could compromise driving, the operation of machinery or high-risk activities warrants a particularly careful assessment.