Insomnia, also known as sleeplessness, is a sleep disorder causing difficulty falling asleep or staying asleep for as long as desired. Insomnia is typically followed by daytime sleepiness, low energy, irritability, and a depressed mood. It may result in an increased risk of accidents as well as problems focusing and learning. Insomnia can be short-term, lasting for days or weeks, or long-term, lasting more than a month. The concept of the word insomnia has two distinct possibilities: insomnia disorder or insomnia symptoms.
Insomnia can occur independently or as a result of another problem. Conditions that can result in insomnia include psychological stress, chronic pain, heart failure, hyperthyroidism, heartburn, restless leg syndrome, perimenopause, menopause, certain medications, and use of drugs such as caffeine, nicotine, and alcohol. Risk factors include working night shifts and sleep apnea. Diagnosis is based on sleep habits and an examination to look for underlying causes. A sleep study may be done to look for underlying sleep disorders. Screening may be done with questions like "Do you experience difficulty sleeping?" or "Do you have difficulty falling or staying asleep?"
Cognitive behavioral therapy is considered the first-line treatment. Sleep hygiene and lifestyle changes are also recommended for insomnia, though their efficacy is not definitely established. Sleep hygiene includes a consistent bedtime, a quiet and dark room, exposure to sunlight during the day and regular exercise. Sleeping pills can improve sleep, though some are associated with falls, cognitive impairment, and dependence. These medications are not recommended for more than four or five weeks but can be used longer in certain instances. Among these, lemborexant and eszopiclone have the most favorable efficacy and safety profiles. The efficacy and safety of alternative medicine treatments are unclear.
Between 10% and 30% of adults have insomnia at any given point in time, and up to half of people have insomnia in a given year. About 6% of people have insomnia that is not due to another problem and lasts for more than a month. People over the age of 65 are affected more often than younger people. Women are more often affected than men. Descriptions of insomnia occur at least as far back as ancient Greece. Anthropological research has also examined how insomnia and sleep disturbance may be influenced by cultural, social, and biological factors working together. Research on industrialisation has considered the effects of artificial light, urban development, and changing work habits on sleep, suggesting that experiences of insomnia are not shaped solely by biological processes. Cross-cultural research has also shown that ideas about what constitutes ‘normal’ sleep can vary between societies, influencing how sleep difficulties are understood and experienced.
Signs and symptoms
Symptoms of insomnia: Difficulty falling asleep, including difficulty finding a comfortable sleeping position Waking during the night, being unable to return to sleep, and waking up early Not able to focus on daily tasks, difficulty in remembering Daytime sleepiness, irritability, depression or anxiety Feeling tired or having low energy during the day Trouble concentrating Being irritable, acting aggressive, or impulsive Memory impairment Sleep onset insomnia is difficulty falling asleep at the beginning of the night, often a symptom of anxiety disorders. Delayed sleep phase disorder can be misdiagnosed as insomnia, as sleep onset is delayed much later than normal, while awakening spills over into daylight hours.
It is common for people who have difficulty falling asleep to also have nocturnal awakenings with difficulty returning to sleep. Two-thirds of these people wake up in the middle of the night, with more than half having trouble falling back to sleep after a middle-of-the-night awakening.
Early morning awakening occurs earlier (more than 30 minutes) than desired, with an inability to go back to sleep and before total sleep time reaches 6.5 hours. Early morning awakening is often a characteristic of depression. Anxiety symptoms may well lead to insomnia. Some of these symptoms include psychological stress, compulsive worrying about the future, feeling overstimulated, and overanalyzing past events.
Chronic insomnia may take a mental toll, affecting social interactions, work, and lifestyle.
Poor sleep quality Poor sleep quality can occur as a result of, for example, restless legs, sleep apnea, or major depression. Poor sleep quality is defined as the individual not reaching stage 3 or delta sleep, which has restorative properties.
Major depression leads to alterations in the function of the hypothalamic–pituitary–adrenal axis, causing excessive release of cortisol, which can lead to poor sleep quality.
Nocturnal polyuria, excessive night-time urination, can also result in a poor quality of sleep.
Subjectivity
Sleep state misperception is a condition where people believe that they have been awake all night even though sleep tests prove that they have slept for hours. Also called paradoxical insomnia or subjective insomnia, paradoxical insomnia may affect only about 5% of people with insomnia.
Despite sleeping for multiple hours each night and typically not experiencing significant daytime sleepiness or other symptoms of sleep loss, patients feel like they have not slept very much, if at all. They incorrectly believe it takes them an abnormally long time to fall asleep, and they underestimate how long they stay asleep.
Problematic digital media use
Causes
While insomnia can be caused by many conditions, it can also occur without any identifiable cause. This is known as Primary Insomnia. Primary Insomnia may also have an initial identifiable cause but continues after the cause is no longer present. For example, a bout of insomnia may be triggered by a stressful work or life event. However, the condition may continue after the stressful event has been resolved. In such cases, the insomnia is usually perpetuated by the anxiety or fear caused by the sleeplessness itself, rather than any external factors.
Symptoms of insomnia can be caused by or associated with: Sleep breathing disorders, such as sleep apnea or upper airway resistance syndrome Use of psychoactive drugs (such as stimulants), including certain medications, herbs, caffeine, nicotine, cocaine, amphetamines, methylphenidate, aripiprazole, MDMA, modafinil, or excessive alcohol intake Use of or withdrawal from alcohol and other sedatives, such as anti-anxiety and sleep drugs like benzodiazepines Use of or withdrawal from pain-relievers such as opioids Heart disease Restless legs syndrome, which can cause sleep onset insomnia due to the discomforting sensations felt and the need to move the legs or other body parts to relieve these sensations Periodic limb movement disorder (PLMD), which occurs during sleep and can cause arousals of which the sleeper is unaware Pain: an injury or condition that causes pain can preclude an individual from finding a comfortable position in which to fall asleep, and can also cause awakening. Hormone shifts such as those that precede menstruation and those during perimenopause and menopause Life events such as fear, stress, anxiety, emotional or mental tension, work problems, financial stress, birth of a child, and bereavement Gastrointestinal issues such as heartburn or constipation Mental, neurobehavioral, or neurodevelopmental disorders such as bipolar disorder, clinical depression, generalized anxiety disorder, post-traumatic stress disorder, schizophrenia, obsessive–compulsive disorder, autism, dementia, ADHD, and fetal alcohol spectrum disorder Disturbances of the circadian rhythm, such as shift work and jet lag, can cause an inability to sleep at some times of the day and excessive sleepiness at other times of the day. Chronic circadian rhythm disorders are characterized by similar symptoms. Certain neurological disorders such as brain lesions, or a history of traumatic brain injury Medical conditions such as hyperthyroidism Abuse of over-the-counter or prescription sleep aids (sedative or depressant drugs) can produce rebound insomnia Poor sleep hygiene, e.g., noise or over-consumption of caffeine A rare genetic condition can cause a prion-based, permanent, and eventually fatal form of insomnia called fatal familial insomnia Physical exercise: exercise-induced insomnia is common in athletes in the form of prolonged sleep onset latency Increased exposure to the blue light from artificial sources, such as phones or computers Chronic pain Lower back pain Asthma Parkinson's disease
Sleep studies using polysomnography have suggested that people who have sleep disruption have elevated night-time levels of circulating cortisol and adrenocorticotropic hormone. They also have an elevated metabolic rate, which does not occur in people who do not have insomnia but whose sleep is intentionally disrupted during a sleep study. Studies of brain metabolism using positron emission tomography (PET) scans indicate that people with insomnia have higher metabolic rates by night and by day. The question remains whether these changes are the causes or consequences of long-term insomnia.
Genetics
Heritability estimates of insomnia vary between 38% in males to 59% in females. A genome-wide association study (GWAS) identified 3 genomic loci and 7 genes that influence the risk of insomnia and showed that insomnia is highly polygenic. In particular, a strong positive association was observed for the MEIS1 gene in both males and females. This study showed that the genetic architecture of insomnia strongly overlaps with psychiatric disorders and metabolic traits.
It has been hypothesized that epigenetics might also influence insomnia through a controlling process of both sleep regulation and brain-stress response, having an impact as well on brain plasticity.
Substance-induced
Alcohol-induced
Alcohol is often used as a form of self-treatment for insomnia to induce sleep. However, alcohol use to induce sleep can be a cause of insomnia. Long-term use of alcohol is associated with a decrease in NREM stage 3 and 4 sleep as well as suppression of REM sleep and REM sleep fragmentation. Frequent moving between sleep stages occurs with awakenings due to headaches, the need to urinate, dehydration, and excessive sweating. Glutamine rebound also plays a role when someone is drinking; alcohol inhibits glutamine, one of the body's natural stimulants. When the person stops drinking, the body tries to make up for lost time by producing more glutamine than it needs.
The increase in glutamine levels stimulates the brain while the drinker is trying to sleep, keeping them from reaching the deepest levels of sleep. Stopping chronic alcohol use can also lead to severe insomnia with vivid dreams. During withdrawal, REM sleep is typically exaggerated as part of a rebound effect.
Caffeine
Some people experience sleep disruption or anxiety if they consume caffeine. Doses as low as 100 mg/day, such as a cup of coffee or two to three servings of caffeinated soft-drink, may continue to cause sleep disruption, among other intolerances. Non-regular caffeine users have the least caffeine tolerance for sleep disruption. Some coffee drinkers develop tolerance to its undesired sleep-disrupting effects, but others apparently do not.
Benzodiazepine-induced