Insomnia: causes and prevention

What causes insomnia?

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"), 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 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.
• Vigorous exercise close to bedtime

Prevention of insomnia

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.

Home treatment to prevent insomnia

Many sleep problems can be overcome by simple, common-sense 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 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.

(Prof M. Simpson, MB., BS. (London ); MRCS, LRCP; MRCPsych, DPM).