Insomnia is the inability to sleep, or to sleep satisfactorily, and is the most common sleep disorder. It may involve restless or interrupted sleep, a reduction in the usual time you spend sleeping or, in rare cases, complete wakefulness. Insomnia is a symptom rather than an illness in itself: in the majority of cases, sleeplessness has an underlying cause. When no underlying cause can be found, a person is said to be suffering from primary 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, lower work productivity and may worsen medical and psychological conditions. These consequences make insomnia an important health problem that deserves serious attention.
Insomnia may be caused by the following:
- Emotional distress, especially from internalised anger or anxiety.
- Overusing substances such as caffeine (in coffee, colas and some "energy drinks" like Red Bull), nicotine, certain medications and 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.
- Medical conditions. Many illnesses, such as 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, say from arthritis or leg cramps, can also cause sleep problems. Insomnia may be associated with an underlying psychiatric condition, 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 apnea (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.
- Vigorous exercise close to bedtime.
Who gets it and who is at risk?
Over 90% of people will experience insomnia at some point in their lives, and for the vast majority this will be transient insomnia. Approximately 30% of the population suffers from chronic insomnia.
Those at risk of increased insomnia are:
- Women. Women appear to be more prone to insomnia than men. The following factors may also contribute to the condition:
- The menstrual cycle. Studies have found that 50% of menstruating women reported bloating that disturbed their sleep for two to three days each cycle. Women who suffer from Pre-Menstrual Syndrome may have symptoms of anxiety, irritability or depression, which may lead to insomnia.
- Menopause. Sleep patterns tend to change with menopause, and insomnia becomes more common.
- Pregnancy. Sleeplessness is common during pregnancy, especially in the later weeks.
- Elderly people. Ageing brings a change in sleeping patterns, resulting in typically lighter, more fitful sleep.
- People with a history of depression.
Symptoms and signs
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, people may feel fatigued, depressed, anxious or irritable.
- People with insomnia often suffer from daytime sleepiness.
- Forgetfulness and trouble concentrating.
To diagnose the cause of insomnia, your doctor will perform a complete physical exam and take a medical history, which will include your lifelong sleep patterns, previous experiences of insomnia and recent life stresses. Be sure to tell your doctor about any prescription or non-prescription medications you might be taking, as well as stimulants such as coffee. He or she 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 are unaware. Your doctor 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 the medical history and physical examination. If there is evidence of an additional sleep disorder, such as sleep apnea, your doctor may recommend a sleep study, or "nocturnal polysomnography". These studies are usually done in a sleep laboratory in a medical centre, where you spend the night in a hospital-type room while specialised machines monitor your heart, lung, brain and muscle activity.
Insomnia can often be prevented if you identify and deal with problems that could cause or exacerbate insomnia, such as underlying medical problems, like depression, or behaviours such as caffeine consumption.
However, when treatment of medical or behavioural factors does not improve the insomnia or when there is no apparent underlying cause (as in primary insomnia), your doctor may recommend other treatment methods.
Transient and intermittent insomnias may resolve on their own if they are due to 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. Anyone taking sleeping pills should be closely supervised to evaluate the drug's effectiveness and side effects. Take the lowest dose necessary to relieve your symptoms.
Prescribed sleeping medications can be useful in some cases of insomnia and, when used properly, can be the quickest form of treatment. However, they should be considered as a temporary solution only. After a few weeks, they may lose their effectiveness, making some people raise the dosage. There is a risk of physical addiction to these medications and of injury from falls when getting up at night to use the bathroom (especially 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.
Never combine sleep-inducing drugs with even a small amount of alcohol, as this is a sedative which can compound their effects.
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 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.
- Sleep therapy 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 sleep at the same time each day.
- Melatonin: a hormone produced by the pineal gland. Small amounts may help regulate the sleep cycle in people with a deficiency. Despite its widespread use for insomnia, little is known about melatonin. However, many of the melatonin products available contain unknown substances, so it should be used with caution.
- Camomile: a calming, relaxing tea.
- Valerian: a herbal tranquilliser that helps relax muscles.
Always tell your doctor when you are using alternative therapies as they may interact with prescription drugs, and often have side effects of their own.
Home treatment and prevention
Many sleep problems can be overcome by simple, commonsense measures:
- Cut down on late-night snacks and late-evening heavy dinners. Some experts recommend that you should not eat at least three hours before bedtime. Protein promotes alertness and carbohydrates calm and drowsiness, 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 control stress and releases natural stimulants, decreasing the need for external stimulants such as caffeine. An exercise routine should help regulate your sleep cycles 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 are 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 is converted into a sleep-enhancing compound in the brain). Many people feel relaxed after sex. Relaxation techniques (see 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.
Reviewed by Dr Kevin Rosman, neurologist in sleep disorders, June 2010