Insomnia refers to the inability to fall sleep or to maintain sleep, or waking up early and not getting enough sleep.
While occasional insomnia as a symptom is very common, “insomnia disorder” is a medically classifiable condition in which the above symptoms are associated with impaired functioning during the day. The insomnia should also last for more than a month for the “insomnia disorder” diagnosis to apply.
Insomnia is the most common sleep disorder. The International Classification of Sleep Disorders (ICSD-3) defines insomnia disorder as follows: “Insomnia is a persistent difficulty with sleep initiation, duration, consolidation, or quality that occurs despite adequate opportunity and circumstances for sleep, and results in some form of daytime impairment. When no underlying cause can be found, a person is said to be suffering from primary insomnia. Where a cause is found (for example, a medical condition), it’s classified as secondary insomnia.”
Insomniacs may experience loss of energy and enthusiasm, have problems with memory and concentration, and may feel ill, sleepy and frustrated. Poor sleep can be associated with accidents and lower work productivity, and may worsen medical and psychological conditions. These consequences make insomnia an important health problem that deserves serious attention.
Who gets insomnia?
Research points to a global prevalence of acute (short-term) insomnia in approximately 30% of the adult population, with chronic insomnia (insomnia disorder) affecting approximately 10% of the population.
Insomnia is common in women, older adults and people with medical and mental-health problems. It also occurs more frequently in people who work irregular shifts or who have disabilities.
Personal or work stress, noise, drug and substance abuse, and the use of certain medications (e.g. certain antidepressants, beta blockers and corticosteroids) may contribute to insomnia.
Symptoms of insomnia
Insomnia typically involves the following symptoms:
- Difficulty falling asleep and maintaining sleep, or waking up too early.
- Waking up feeling unrefreshed or drowsy. In more severe cases of insomnia, you may feel fatigued, depressed, anxious or irritable.
- People with insomnia often suffer from daytime sleepiness and fatigue.
- Forgetfulness and trouble concentrating.
What causes insomnia?
Insomnia may be caused by the following:
- Emotional distress, especially from internalised anger or anxiety.
- Overusing stimulant substances such as caffeine (found in coffee, colas, chocolate and some energy drinks like Red Bull), nicotine, certain medications, herbal remedies, and alcohol. Alcohol consumption may cause initial drowsiness, but this is usually followed by sudden wakefulness once the alcohol is metabolised. Paradoxically, insomnia may result from sedatives prescribed to relieve it. Some people, especially the elderly, develop an inverted sleep rhythm: drowsiness in the morning, sleep during the day, and wakefulness at night.
- Disturbances in your body clock or circadian rhythm. This may be the result of an irregular sleep schedule due to, for example, excessive daytime napping or late-night partying. Disturbance of sleep timing is common in people travelling by plane to different time zones, night-shift workers and high-school and university students doing "all-nighters" when cramming for tests.
- Environmental factors such as noise, extreme temperatures, bright lights and sleeping in unfamiliar surroundings can cause transient and intermittent insomnia.
- Many illnesses, including ulcers, depression, diabetes, kidney disease, heart failure, Parkinson's disease and hyperthyroidism, may lead to chronic insomnia. Shortness of breath from asthma or other medical problems, heartburn, frequent urination and chronic pain (e.g. from arthritis or leg cramps) can also cause sleep problems.
- Insomnia may be associated with an underlying psychiatric conditions such as depression or schizophrenia. Early morning waking is common in some acutely depressed people. Other sleep disorders may also lead to chronic insomnia.
- Sleep disorders. Sleep apnoea (snoring with numerous or prolonged breathing pauses during sleep), narcolepsy (inability to control staying awake or falling asleep), periodic leg and arm movements during sleep (the muscles twitch or jerk excessively), or restless legs syndrome (an overwhelming need to move the legs) can all interfere with sleep onset and maintenance.
- Eating large meals close to bedtime.
- Doing vigorous exercise close to bedtime.
Risk factors for insomnia
Those at risk of increased insomnia are:
1. Women. The following factors may contribute to the condition in females:
- The menstrual cycle. Studies have found that 50% of menstruating women report bloating that disturb their sleep for 2-3 days during each cycle. Women who suffer from pre-menstrual syndrome (PMS) may furthermore experience symptoms of anxiety, irritability or depression, which may lead to insomnia. The London Sleep Centre provides a more in-depth review of sleep in women.
- Menopause. Sleep patterns tend to change with menopause and insomnia becomes more common.
- Pregnancy. Sleeplessness is common during pregnancy, especially in the last trimester.
2. Elderly people. Ageing brings a change in sleeping patterns, resulting in typically lighter, more fitful sleep.
3. People with a history of depression and/or anxiety disorders.
Course and prognosis of insomnia
Insomnia may arise suddenly (acute) or gradually (chronic). In acute insomnia, there’s usually a triggering factor that can be identified – for example separation, bereavement, change in sleep schedule, or an increase in daily stress levels.
By definition, acute insomnia is short-lived and can usually be easily managed by a short course of sleeping tablets and counselling addressing the triggering factors.
Chronic insomnia has a more insidious onset over a period of time and its course can be situational, recurrent or persistent. The earlier you seek help for insomnia, the better the clinical outcome.
How is insomnia diagnosed?
To diagnose the cause of insomnia, your doctor will perform a complete physical examination and take a medical history. This will include a history of your lifelong sleep patterns, previous experiences of insomnia, and recent life stresses. Be sure to tell your doctor about any prescription or non-prescription medication you might be taking, as well as stimulants such as coffee.
Your doctor may also want to interview your sleeping partner about your sleep patterns, as your partner may observe aspects of your behaviour during sleep of which you’re unaware. He or she may also ask you and your partner to keep diaries of your sleep patterns for a few weeks.
In most cases, the cause will become apparent through your medical history and the physical examination. If there’s evidence of an additional sleep disorder, such as sleep apnoea, your doctor may recommend a sleep study, or "nocturnal polysomnography".
These studies are usually done in a sleep laboratory in a medical centre. You’ll have to spend the night in a hospital-type room while specialised machines will monitor your heart, lung and brain, as well as your muscle activity.
How is insomnia treated?
Transient and intermittent insomnias may resolve on their own if they’re the result of a temporary disruption in your sleep schedule.
However, if the insomnia is caused by a particularly stressful situation or pain from some physical condition, or if daily efficiency and quality of life are seriously impaired by sleeplessness, your doctor may prescribe short-acting sleeping pills.
If you’re taking sleeping pills, you should be closely monitored to evaluate the drug's effectiveness and side effects. It’s also important to take the lowest dose necessary to relieve your symptoms.
Prescribed sleeping medications can be useful in some cases of insomnia. When used properly, it can also be the quickest form of treatment. However, these medicines should be used as a temporary solution only. After a few weeks, they may lose their effectiveness, making some people raise the dosage. There’s also a risk of physical addiction to these medications, as well as injury from falls when getting up at night to use the bathroom (this is especially true for older people.)
Over-the-counter medications often complicate insomnia. They may help you fall asleep, but sleep quality is usually poor. Long-term use often worsens insomnia and makes it more difficult to treat. Use these medications only if your doctor recommends them.
Supplemental melatonin has recently undergone regulatory intervention, and is now only available by prescription for the treatment of insomnia. Melatonin is a hormone produced by the pineal gland in the brain. Small amounts in supplement form may help regulate the sleep cycle in people with circadian rhythm disorders and chronic insomnia. It’s particularly useful in the elderly.
Important note: Never combine sleep-inducing drugs with even a small amount of alcohol. Alcohol is a sedative that can compound the drug’s effects.
The gold-standard, evidence-based treatment for insomnia uncomplicated by a medical or psychiatric condition is cognitive behavioural therapy for insomnia (CBT-I).
CBT-I utilises the following techniques and interventions to help you restore your normal (physiological) sleep:
- Sleep hygiene (good sleep habits)
- Relaxation therapy
- Stimulus control
- Sleep restriction
- Cognitive therapy (addressing negative automatic thoughts)
- Behavioural adjustments
Behavioural techniques can be as effective as sleeping pills and have no side effects. The goal is to help you "learn" healthy sleeping habits. Examples of behaviour therapy include:
- Relaxation therapy. This aims to relax the mind and muscles by focusing on the repetition of a word, sound or muscular activity (tensing and releasing muscles while lying in bed), without actively excluding other thoughts or feelings. The aim is to relax passively by accepting each thought or emotion as it arises.
- Restriction of sleep. This involves allowing a few hours of sleep during the night and gradually increasing the time until you reach a normal night's sleep.
- Reconditioning aims to alter how you associate your bed and bedtime with sleep. You avoid using the bed for anything but sleep and intimacy, go to bed only when sleepy, and leave the bedroom if you can't sleep. You also learn to avoid naps, and to sleep at the same time each day.
The following remedies may help with sleep:
- Camomile: This is a calming, relaxing tea.
- Kava-kava: This Pacific-island root may help alleviate anxiety and encourage restful sleep. However, habitual use of high doses has been associated with serious side effects such as muscle weakness and a skin rash. Use with caution, in low doses and intermittently.
- Valerian: This herbal tranquilliser helps to relax muscles.
Important note: Always tell your doctor when you’re using alternative therapies as they may interact with your prescription drugs. They also often have side effects of their own.
Home treatment and prevention
Many sleep problems can be overcome by simple measures (also known as good sleep hygiene):
- Cut down on late-night snacks and late-evening heavy dinners. Some experts recommend that you shouldn’t eat at least three hours before bedtime. Protein promotes alertness and carbohydrates make you calm and drowsy, so eat a light, high-protein, low-carbohydrate lunch. This will decrease early-afternoon drowsiness, and make an afternoon nap less tempting. Conversely, a high-carbohydrate, low-protein supper should help encourage sleepiness closer to bedtime.
- Exercise. Even moderate exercise helps to control stress while releasing natural stimulants, decreasing the need for external stimulants such as caffeine. An exercise routine should help regulate your sleep cycle and make you feel sleepier in the late evening. However, avoid exercising vigorously too close to bedtime.
- Don't use your bedroom, even less your bed, as a place for activities other than sleep and intimacy. Get into bed when you’re ready to sleep and leave it when you wake, to avoid sending your body conflicting cues about sleep and waking life.
- If you wake up in the middle of the night and can't fall asleep within half an hour, get up and rest, or read in a comfortable chair until you become sleepy.
- Establish a bedtime ritual of cues for going to sleep. These could include having a bath or drinking a glass of warm milk (milk contains an amino acid that’s converted into a sleep-enhancing compound in the brain). Many people feel relaxed after sex.
- Relaxation techniques (see ‘Behavioural therapy’ above) may also be useful.
- Cut down on daytime napping if it starts to affect your regular sleep patterns. Avoid napping within seven or eight hours of bedtime.
- Avoid alcohol in the late evening.
- If your insomnia persists, keep a diary of your sleep history. This may be helpful later in diagnosing an underlying cause.
Insomnia: when to call a doctor
The majority of people with insomnia symptoms usually have short-term situational insomnia that resolves by itself.
However, if your insomnia has been present for more than a couple of weeks and isn’t improving despite you establishing good sleep hygiene practices (see ‘Treatment’ section) and/or you’re developing daytime fatigue, irritability and poor concentration, it’s time to get your doctor involved.
How can insomnia be prevented?
Insomnia can often be prevented by identifying and dealing with problems that could cause or exacerbate sleeplessness, such as underlying medical problems (e.g. depression or anxiety), or behaviours such as caffeine and alcohol consumption.
However, when treatment of medical or behavioural factors doesn’t improve the insomnia, or when there’s no apparent underlying cause (as in primary insomnia), your doctor may recommend other treatment methods.
Reviewed by Dr Irshaad Ebrahim, specialist neuropsychiatrist in sleep disorders at The London Sleep Centre and The Constantia Sleep Centre. FRCPsych. April 2018.