by Dr. Milton Lum
The body rests and recovers from previous activities during sleep. Normal sleep comprises cycles of non-rapid eye movement (NREM) and rapid eye movement (REM). NREM sleep is followed by REM sleep, which occurs 4 to 5 times during the usual 8-hour sleep period.
The first REM period of the night may be last less than 10 minutes, while the last may exceed an hour. The NREM and REM cycles vary in length from 70 to 100 minutes initially, to 90 to 120 minutes later in the night.
During the first third of the night, deep NREM sleep predominates, while REM sleep predominates in the last third of the night. REM sleep takes up 20% to 25% of total sleep time.
Insomnia
Insomnia refers to the disturbance of a normal sleep pattern. The different types of insomnia are:
* Difficulty getting to sleep (sleep onset insomnia) which is most common in young people.
* Waking up in the night which is most common in older people.
* Waking up early in the morning, which is least common.
* Not feeling refreshed after sleeping, leading to irritability, tiredness and difficulty concentrating during the day.
* Waking up due to disturbances such as noise or pain.
The duration of insomnia varies. It may be :
# Transient, lasting 2 to 3 days
# Short-term, lasting more than a few days, but less than 3 weeks
# Chronic, that is, it occurs on most nights for 3 weeks or more.
Everyone has experienced insomnia. It is generally accepted that about one-third of the population has insomnia.
How Much Sleep?
The need for sleep varies with age. A newborn may sleep 16 to 20 hours, and an infant 12 to 14 hours. Toddlers may sleep 10 hours or more. Primary school children need 9 to 10 hours of sleep, while normal adults need 6 to 10 hours of sleep.
It takes an adult about 10 to 20 minutes to fall asleep. Most of those who have less than 5 to 6 hours of sleep are probably not getting enough sleep.
After a good sleep, a person would feel refreshed on waking and can stay alert throughout the day, without the need for naps or sleeping in on weekends.
Symptoms and Causes
The symptoms of insomnia vary. They include lying awake for a long period at night prior to sleeping, waking up several times at night, waking up early in the morning and not being able to go back to sleep, feeling tired and not refreshed, inability to function properly during the day, and feeling irritable.
The causes of insomnia :
* Physiological : working at night, light, noise, snoring, partner's movements, and jet lag.
* Medical : pain or discomfort caused by arthritis, headaches, back pain, menopausal hot flushes, gastrointestinal disorders and pruritus (excessive itching).
* Psychological and psychiatric : examination stress, work worries, relationship problems, anxiety, depression, bereavement and dementia.
* Sleep disorders : sleep apnoea and sleep walking.
* Medicines : antidepressants, appetite suppressants, beta-blockers, corticosteroids and decongestants.
* Alcohol.
Management
Consult a doctor. He will look into the history of your condition and conduct a physical examination. The doctor will enquire about your sleeping routines, previous and current medical conditions, psychological or psychiatric conditions, if any, consumption of caffeine, medicines and alcohol, substance abuse including narcotic drugs, diet and exercise. The cause may be detected through this approach in many instances.
If the cause is not obvious, the doctor will ask for a sleep diary to be kept. This involves recording the time when one goes to sleep, when one wakes up in the morning and when one wakes up at night.
A referral to a specialist may be necessary if the cause is still not obvious. Laboratory tests and polysomnography may be carried out. The latter is used in the diagnosis of sleep apnoea and sleep disorders. This involves recording many parameters when one is asleep, including brain electrical activity; movements of the eye, jaw and leg muscles; and heart and lung functions. The doctor will discuss with the patient prior to any videotaping which may be considered necessary.
Once a diagnosis of the underlying condition has been made, the cause will be treated. For example, if the cause is anxiety or depression, the problem will go away once it is treated.
General measures which do not involve the use of medicines are preferred. It may involve counselling if the insomnia is due to stress or bereavement. Cognitive behavioural therapy which involves changes in thinking and behavioural patterns is useful. Measures like limiting caffeine or alcohol intake, exercise and keeping to a regular sleep routine are helpful.
Sleeping pills may be considered by the doctor for severe or short-term insomnia if general measures do not work. Doctors are usually reluctant to prescribe sleeping pills as they relieve the symptoms but do not address the underlying cause. An individual can also become dependent on sleeping pills, which are not without side effects.
Many of the sleeping pills available belong to a group of medicines called benzodiazepines which require a doctor's prescription. Benzodiazepines are anxiolytics and hypnotics, that is, they reduce anxiety and promote calmness and sleep. Benzodiazepines can lead to dependence and side effects like a hangover and drowsiness during the day. This can lead to accidents when driving. Examples of benzodiazepines include lormetazepam and temazepam.
The short-acting 'Z-pills' that is, zopiclone and zolpidem, act on the same receptors as benzodiazepines but are not classified as such because their molecular structures are different. They were initially thought to be less addictive and habit forming than benzodiazepines but this view has changed with reports of addiction in the past few years. The side effects are similar to benzodiazepines.
The lowest possible dose of sleeping pills should be taken for the shortest possible time. One should only take them under medical supervision. There is no place for self-medication. Do not stop intake abruptly as this may cause withdrawal effects. The doctor's advice is crucial here.
Melatonin is a hormone that is involved in the regulation of the sleep cycle or circadian rhythm. It is a short-term medicine for insomnia and cannot be consumed for more than 3 weeks. Although side effects are uncommon, they include dizziness, migraines, irritability, constipation and abdominal discomfort.
Getting Good Sleep
Getting a good night's sleep is vital. This can be achieved by various means :
* Having a routine facilitates sound sleep. This means going to bed and getting up at about the same time every day. It is important to relax before getting into bed as activity just before bedtime may keep one awake.
* Having an early dinner helps. The digestive system goes to sleep at about 7 o'clock. A light dinner is helpful.
* Avoid caffeine after lunch as caffeine keeps one awake.
* Avoid alcohol as its breakdown produces chemicals that stimulate the individual. It also increases the likelihood of snoring as it relaxes the muscles. This leads to lighter and less refreshing sleep.
* Avoid naps. The afternoon nap may keep one awake at night.
* Avoid light. This is because melatonin, the hormone that helps a person sleep, is produced in the dark.
More info on INSOMNIA here.
