Sleep

 Sleep

Sleep is as essential for good health as oxygen, food and water. Yet we still don’t know exactly what it is or how it works. Most scientists agree that sleep is important for restoring physical and mental health. It refreshes the mind and repairs the body. Lack of sleep, or sleep deprivation, can cause fatigue, poor concentration and memory, mood disturbances, impaired judgement and reaction time, and poor physical coordination.
The body’s internal clock regulates when and how we sleep depending on the amount of light around us. When the sun sets, your brain releases hormones to make you sleepy. In the morning, exposure to daylight suppresses these hormones and releases brain chemicals to keep you awake
Getting enough sleep
Before electricity, people used to sleep between sunset and sunrise. The typical person’s sleep averaged a generous ten hours – the same amount enjoyed by other primates like chimpanzees and baboons. Today, sleep deprivation is common in developed nations, with the average adult sleeping for only six or seven hours each night.
Most of us feel fatigued at least some of the time. It is thought that fatigue causes about one road accident in six. Studies show that a common distraction from sleep is the Internet and more recently, texting. Parenthood, shift work, travel across time zones, illness, poor sleeping habits and some medications are other common sleep-stealers. New parents lose, on average, between 450 and 700 hours of sleep during their child’s first 12 months of life
Sleep stages
Sleep isn’t a static state of consciousness. The brain moves through distinct stages of sleep, over and over, every night. The two broad categories of sleep include:
    Rapid eye movement (REM) sleep
    Non-rapid eye movement (NREM) sleep.
Rapid eye movement (REM) sleep
Rapid eye movement sleep occurs regularly, about once every 90 to 120 minutes. It makes up about one-quarter of your night’s sleep. The brain in REM sleep shows significant electrical activity. The sleeper’s eyes tend to dart about under closed lids, hence the name.
The bulk of dreams are thought to occur during REM sleep. Sleep researchers have established that at least some eye movements correspond with dream content, which suggests that we watch our dreams like we watch movies on a screen. REM sleep makes up a larger proportion of the total sleep period in babies (especially premature babies), which suggests that dreams help to mature a developing brain.
Non-rapid eye movement (NREM) sleep
Non-rapid eye movement sleep is what you experience for the remaining three-quarters of your sleep time. The amount and type of NREM sleep vary with age and the degree of sleep deprivation.
The four broad stages of NREM sleep include:
    Stage 1 – Dozing or drowsiness. You hover between being asleep and awake.
    Stage 2 –You lose awareness of your surroundings. Body temperature starts to drop. Breathing and heart rate slow down.
    Stages 3 and 4 – Deep sleep, also known as ‘delta sleep’. Your blood pressure, heart rate and breathing become very slow and your muscles relax. Growth and repair processes occur during this stage.

Sleep disorders

 Some of the sleep disorders that may contribute to or cause excessive daytime sleepiness include:
    Sleep apnoea – the person’s breathing stops or is reduced regularly during sleep, sometimes every minute. The brain registers the breathing problem and sends a ‘wake-up’ call. The person rouses slightly, gasps and then goes back to sleep. Sleep is fragmented.
    Insomnia – this is very common, but does not necessarily cause hypersomnia. A person may have difficulty getting to sleep or staying asleep. Insomnia is a symptom, not a disease.
    Restless legs syndrome – sensations of cramps or irritation are felt under the skin in the legs, particularly the calves. The person feels compelled to move their legs or get out of bed and walk around.
    Sleep walking – this is a common abnormal behaviour during sleep. The person may walk around the house while still asleep. Sleep walking tends to affect children more than adults.
    Narcolepsy – this is a relatively rare sleep disorder characterised by sleepiness to the degree of involuntary napping, paralysis of the muscles (sleep paralysis), vivid, dream-like hallucinations just prior to falling asleep (hypnagogic hallucinations), and muscle weakness during periods of strong emotion (cataplexy).
    Idiopathic hypersomnia – this sleep disorder is characterised by excessive night-time sleeping and the need for naps during the day. Unlike narcolepsy, it doesn’t include cataplexy or sleep paralysis

Sleep apnoea

 Sleep apnoea occurs when the walls of the throat come together during sleep, blocking off the upper airway. Breathing stops for a period of time (generally between a few seconds and up to one minute) until the brain registers the lack of breathing or a drop in oxygen levels and sends a small wake-up call. The sleeper rouses slightly, opens the upper airway, typically snorts and gasps, then drifts back to sleep almost immediately.
In most cases, the person suffering from sleep apnoea doesn’t even realise they are waking up. This pattern can repeat itself hundreds of times every night, causing fragmented sleep. This leaves the person feeling unrefreshed in the morning, with excessive daytime sleepiness, poor daytime concentration and work performance, and fatigue. It’s estimated that about five per cent of Australians suffer from this sleep disorder, with around one in four men over the age of 30 years affected.
Degrees of severity
The full name for this condition is obstructive sleep apnoea. Another rare form of breathing disturbance during sleep is called central sleep apnoea. It is caused by a disruption to the nerve messages sent between the brain and the body. The severity of sleep apnoea depends on how often the breathing is interrupted. As a guide:
    Normal – less than five interruptions an hour
    Mild sleep apnoea – between 5 and 15 interruptions an hour
    Moderate sleep apnoea – between 15 and 30 interruptions an hour
    Severe sleep apnoea – over 30 interruptions an hour.
Symptoms of sleep apnoea
People with significant sleep apnoea have an increased risk of motor vehicle accidents and high blood pressure, and may have an increased risk of heart attack and stroke. In the over-30 year age group, the disorder is about three times more common in men than women. Some of the associated symptoms include:
    Daytime sleepiness, fatigue and tiredness
    Poor concentration
    Irritability and mood changes
    Impotence and reduced sex drive
    Need to get up to toilet frequently at night
Causes of sleep apnoea
Obesity is one of the most common causes of sleep apnoea. A loss of around 5kg to 10kg may be enough to dramatically reduce the severity of the disorder. Other contributing factors include:
    Alcohol, especially in the evening – this relaxes the throat muscles and hampers the brain’s reaction to sleep disordered breathing
    Certain illnesses, like reduced thyroid production or the presence of a very large goitre
    Large tonsils, especially in children
    Medications, such as sleeping tablets and sedatives
    Nasal congestion and obstruction
    Facial bone shape and the size of muscles, such as an undershot jaw.
Treatment for sleep apnoea
Treatment for sleep apnoea relies on changes to lifestyle, including losing weight and cutting down on alcohol. Any contributing medical condition, such as low production of thyroid hormone, also needs to be corrected. Any surgical conditions such as large tonsils should be corrected.
The most effective treatment available is a mask worn at night that keeps the back of the throat open by forcing air through the nose. This is called ‘nasal continuous positive airway pressure’ (CPAP). However, some people with sleep apnoea find the mask difficult to tolerate.
Another treatment is the use of a mouthguard (or oral appliance or mandibular advancement splint). They work by holding the jaw forward during sleep. When properly made, they can be effective for mild to moderate sleep apnoea.
Although not always effective, surgery to the palate and base of tongue may be useful when other therapies fail. These types of surgeries are best undertaken by otolaryngologists (ENT surgeons) who take a special interest and have had training in sleep-related surgery.

Insomnia

 Insomnia is a symptom, not a disease. It means being concerned with how much you sleep or how well you sleep. This may be caused by difficulties in either falling or staying asleep. Self-reported sleeping problems, dissatisfaction with sleep quality and daytime tiredness are the only defining characteristics of insomnia. It is an individual perception of sleep. Long-term chronic insomnia needs professional support from a sleep disorder clinic.
The concept of ‘a good sleep’ differs widely from person to person. While the average night’s sleep for an adult is around eight hours, some people only need five, while others like up to 10 hours or more. What seems like insomnia to one person might be considered a good sleep by another.
Insomnia is a common complaint
Over one third of people experience insomnia from time to time, but only around five per cent need treatment for the condition. Transient or short-term insomnia is typically caused by such things as stressful life events, jet lag, changes in sleeping environments, some acute medical illnesses and stimulant medications. Normal sleeping habits return once the acute event is over.
If a person has experienced sleeping difficulties for a month or more, this is called persistent or chronic insomnia. There are many causes of persistent insomnia. These include:
    Secondary insomnia – due to a range of medical and psychiatric problems and the chronic use of drugs and alcohol.
    Primary sleep disorders – include circadian rhythm disorders, central sleep apnoea-insomnia syndrome, inadequate sleep syndromes and periodic limb movement or restless legs syndromes.
    Idiopathic insomnia – sleeplessness without a known cause, formerly called childhood onset insomnia.
Keep sleep in perspective
People who suffer from insomnia are normally frustrated or annoyed by it. Paradoxically, this emotional state contributes to keeping them awake, starting a vicious cycle. It helps to stop expecting a set amount of sleep every night. Having less sleep than you’d like doesn’t cause any harm. Allow yourself to fall short of the ideal without getting anxious about it.
Home remedies for short-term insomnia
Reducing anxiety and sticking to a day–night routine can improve sleep quality. Suggestions include:
    Don’t nap during the day.
    Cut down on smoking and drinking.
    Avoid tea, coffee and other caffeinated drinks before bed.
    Don’t exercise strenuously before bedtime.
    Do something to relax, such as meditate or have a warm bath.
    Only go to bed if you feel sleepy.
    Go to bed later.
    Stop reading, worrying or watching television in bed and limit your activities in the bedroom to sleeping and sex.
    If you can’t sleep, get up, go to another room and do something else until you feel sleepy again.
    Get up at the same time every morning regardless of how much sleep you have had.
    Avoid ‘judging’ your sleep on a day-to-day basis
Treatment for long-term insomnia
Insomnia that has persisted for years needs professional support and a lot of patience. It might take some time to re-establish normal sleeping patterns.
Some of the techniques used by a sleep disorder clinic might include:
    A sleep diary, to help pinpoint the pattern of insomnia
    A program of mild sleep deprivation
    Medication to help set up a new sleeping routine
    Exposure to bright light in the morning
    Behavioural therapy.

Restless legs syndrome (RLS)

Restless legs syndrome (RLS) is an unusual condition of the nervous system characterised by the compelling need to move the legs. It is usually worse in the evening and can be a problem when trying to sleep.
The strange sensation in the calves has been described as a type of cramp, soreness or a creeping, crawling feeling. Some liken the sensation to shooting darts of electricity or even squirming insects inside the legs. The same symptoms can also be caused by other conditions including diabetes, iron deficiency anaemia, alcoholism and some forms of arthritis. It is relatively common in pregnancy.
Around five out of every 100 people will experience RLS at some time. Usually both legs are affected, but it is not uncommon to experience the unpleasant sensations in only one leg. The symptoms can be mild, moderate or severe. In severe cases, the person may be unable to sleep.
No one knows what causes RLS. It can begin at any age, including childhood (although this is thought to be underreported). There is a strong genetic link. Iron deficiency is the most important risk factor.
Restless legs syndrome can affect anyone
Restless legs syndrome can affect people of any age, but certain groups of people tend to be more susceptible, including:
    Middle-aged and elderly people
    Pregnant women
    Those with a parent who experiences RLS (which suggests a genetic link)
    Those who have another sleep disorder called periodic limb movement disorder
    People on antidepressant medication.
Periodic limb movement disorder (PLMD)
Periodic limb movement disorder involves uncontrollable jerking of the legs or, occasionally, the arms. It is also known as ‘sleep myoclonus’. During sleep, these recurring movements can be severe enough to wake the sleeper.
In other cases, the person sleeps, but only lightly, since the jerks rouse them from deep slumber without waking them. The result may be poor sleep quality and daytime fatigue. The jerking can increase or decrease in severity from one night to the next, for no apparent reason.
The cause of PLMD is unknown, but factors that are recognised as being associated with this condition include:
    Being middle-aged or elderly
    Pregnancy
    Iron deficiency
    Renal failure
    The regular use of antidepressants
    A family history of the disorder
    Restless legs syndrome – most people with RLS have PLMD
Sleep deprivation and restless legs syndrome
Standing up, walking or any other exercise that involves the legs can usually relieve the unpleasant physical sensations of RLS. Sleep deprivation is one of the more common side effects of RLS, since sufferers may need to get out of bed and walk around many times every night in order to alleviate the cramps.
The nervous system and RLS
Restless legs syndrome is thought to be caused by some type of malfunction of the motor system and, more specifically, of the dopamine pathway. However, research so far has failed to find any abnormalities in the brains, nerves or muscles of any RLS sufferer.
Treatment of restless legs syndrome
Diagnosing RLS or PLMD is based on symptoms. Since the cause of RLS is unknown, the treatments that are available relieve the symptoms rather than curing the condition.
Some people find that symptoms improve if they cut back or avoid caffeine, alcohol and nicotine. Successfully managing an underlying condition, such as anaemia or diabetes, can sometimes alleviate RLS. As with many sleep disorders, inadequate sleep or sleep deprivation will make RLS worse.
It is very important to correct iron deficiency, after investigation of the cause of the iron deficiency. In some cases, an intravenous infusion (IV drip into your vein) of iron is needed.
In severe cases, medications such as anti-Parkinson disease medications, benzodiazepines or morphine can offer symptom control. Other medications used for RLS include some anti-epileptic medications.

Narcolepsy

 Excessive daytime sleepiness that is not due to a mood disorder or medication is a common health problem that has three broad causes:
    Inadequate quantity of sleep from sleep restriction, sleep deprivation or timing disorders such as jet lag and shift work
    Inadequate quality of sleep due to a problem that fragments sleep such as sleep-disordered breathing, excessive limb movement, chronic pain or chronic illness
    A primary problem with keeping awake and vigilant during the daytime. The term narcolepsy is generally used for this group of disorders
Diagnosis of narcolepsy
Narcolepsy is a rare sleep disorder. A person with narcolepsy has excessive daytime sleepiness, with repeated episodes of sleep attacks, falling asleep involuntarily at inappropriate times, often several times every day. Narcolepsy can develop at any age, but it commonly starts either during the teenage years or in middle age. A person with narcolepsy usually has the condition for life.
All people with narcolepsy have extreme levels of sleepiness during the day, but how this shows itself can differ. For instance, some people with narcolepsy might fall asleep for 10 to 20 minutes several times every day, whether they want to or not. Others with this condition have more control over their naps and can choose when and where they will sleep, such as during lunch breaks.
Since symptoms vary so much between people, a laboratory test called the Multiple Sleep Latency Test can be used to measure daytime sleepiness during four to five naps of 20 minutes. This test may also show if there is very early interruption of REM (rapid eye movement or dreaming) sleep.
Symptoms of narcolepsy
As well as extreme sleepiness and a tendency to fall asleep during the day, other symptoms of narcolepsy all reflect the intrusion of REM sleep outside of established sleep, including:
    Cataplexy – a sudden, brief reversible episode of muscle weakness brought on by a powerful emotional trigger such as laughing or anger. This can cause a collapse without loss of consciousness and can last from a few seconds to minutes. It is thought to be related to the muscle paralysis that occurs to everyone during REM sleep.
    Hypnagogic hallucinations – vivid, dream-like perceptions that happen when the person isn’t quite asleep and may involve hallucinations of sight, sound or feeling (seeing or hearing things).
    Sleep paralysis – at the point of falling asleep, or more often on waking, the person cannot speak or even breathe. This immobilisation can last for a few seconds
Cause of narcolepsy
The hypothalamus is a small structure that sits deep inside the brain. Some of its vital roles include controlling body temperature, appetite and thirst. The hypothalamus is also connected to the reticular activating pathways, which are the brain structures that govern our sleep and wake cycles.
It is thought that narcolepsy is caused by a malfunctioning of the hypothalamus that prevents pathways in the brain from working properly. Instead of introducing sleepy feelings towards the end of each day, narcolepsy prompts random sleepiness.
Some people with narcolepsy have a deficiency of a wake-promoting chemical called orexin or hypocretin. This deficiency is usually present in patients who have narcolepsy-cataplexy.
Treatment for narcolepsy
Treatment depends on the severity of the condition. If the symptoms are mild, simple management and coping techniques, such as making time for naps during the day, are helpful. In more severe cases, medications that stimulate the nervous system are used, such as amphetamine, methylphenidate or modafinil.

Hypersomnia

 Hypersomnia means excessive sleepiness. There are many different causes, the most common in our society being inadequate sleep. This may be due to shiftwork, family demands (such as a new baby), study or social life. Other causes include sleep disorders, medication, and medical and psychiatric illnesses.
Hypersomnia can be helped or cured with a few adjustments to lifestyle habits. Seek advice from your doctor or sleep disorder clinic if you still feel excessively sleepy.
Characteristics of hypersomnia
The characteristics of hypersomnia vary from one person to the next, depending on their age, lifestyle and any underlying causes. Under the International Classification of Sleep Disorders, daytime sleepiness is defined as ‘the inability to stay awake and alert during the major waking episodes of the day, resulting in unintended lapses into drowsiness or sleep’.
In extreme cases, a person with hypersomnia might sleep soundly at night for 12 hours or more, but still feel the need to nap during the day. Sleeping and napping may not help, and the mind may remain foggy with drowsiness. It is possible that a person with hypersomnia may have very disturbed sleep but not be aware of it.
Symptoms of hypersomnia
Depending on the cause, the symptoms of hypersomnia may include:
    Feeling unusually tired all the time
    The need for daytime naps
    Feeling drowsy, despite sleeping and napping – not refreshed on waking up
    Difficulty thinking and making decisions – the mind feels ‘foggy’
    Apathy
    Memory or concentration difficulties
    An increased risk of accidents, especially motor vehicle accidents.
Causes of hypersomnia
Excessive daytime sleepiness can be caused by a wide range of events and conditions, including:
    Insufficient or inadequate sleep – long working hours and overtime can be tolerated for months or years before the symptoms of sleepiness take effect. Teenagers who stay out until the early hours of the morning on weekends may be tired during the week.
    Environmental factors – broken sleep can be caused by a variety of things such as a snoring partner, a baby that wakes, noisy neighbours, heat and cold, or sleeping on an uncomfortable mattress.
    Shiftwork – it is very difficult to get good sleep while working shiftwork, especially night shift. As well as the problem of trying to sleep, there is also the effect of being out of synchronisation with the body’s internal clock (the circadian rhythm).
    Mental states – anxiety can keep a person awake at night, which makes them prone to sleepiness during the day. Depression saps energy.
    Medications – such as alcohol, caffeinated drinks, tranquillisers, sleeping pills and antihistamines can disrupt sleeping patterns.
    Medical conditions – like hypothyroidism (underactive thyroid gland), oesophageal reflux, nocturnal asthma and chronic painful conditions can disrupt sleep.
    Changes to time zone – such as jet lag can affect the internal biological clock, which regulates sleep. This clock responds to light.
    Sleep disorders – such as sleep apnoea, restless legs syndrome, sleep walking, narcolepsy, idiopathic hypersomnia and insomnia may all cause sleep disruption or fragmented sleep.
Self-help strategies
Hypersomnia can be helped in many cases with lifestyle adjustments to improve sleep quality, so called good sleep hygiene. Suggestions include:
    Avoid cigarettes, alcohol and caffeinated drinks near bedtime.
    Follow a relaxation routine to prevent night-time anxiety.
    Exercise regularly and maintain a normal weight for your height.
    Eat a well-balanced diet to prevent nutritional deficiencies.
    If possible, change your environment to reduce disturbances – for example, don’t watch television in the bedroom.
    Be comfortable; make sure you don’t overheat or feel too cold in bed.
    Have a regular sleeping routine so that your body ‘knows’ it is time to sleep.
    Only go to bed when you feel sleepy.
    If necessary, take brief ‘power’ naps during the day to help you stay alert and vigilant. Daytime napping is generally not recommended when improved sleep is possible, as it can reduce the drive to sleep at night. However, brief naps can be very valuable in occupational settings and on other occasions where concentration is required, such as preparation for driving or in regular breaks on a long trip

Other sleepiness conditions

     Sleep restriction – from not getting enough sleep due to late nights from social activities, TV or computer use
    Jet lag, shift work – the brain’s internal ‘clock’ sets our sleep and wake cycles to coincide with day and night, and this rhythm is disrupted by moving to a different time zone or sleeping routine
    Depression – lethargy to the point of sleepiness is a symptom of this emotional disorder
    Snoring with or without sleep apnoea – broken sleep over a period of time leads to a sleep debt, which causes daytime sleepiness
    Fatigue, lethargy and lack of energy – common problems that often need to be investigated to exclude sleepiness
    Chronic fatigue syndrome – thought to be triggered by a viral infection. Other symptoms include weakness, aching muscles, sore throat and headaches

Sleep hygiene

Sleep hygiene’ means habits that help you to have a good night’s sleep. Common sleeping problems (such as insomnia) are often caused by bad habits reinforced over years or even decades. You can dramatically improve your sleep quality by making a few minor adjustments to lifestyle and attitude.
Obey your body clock
The body’s alternating sleep-wake cycle is controlled by an internal ‘clock’ within the brain. Most bodily processes (such as temperature and brain states) are synchronised to this 24-hour physiological clock. Getting a good sleep means working with your body clock, not against it. Suggestions include:
    Get up at the same time every day. Soon this strict routine will help to ‘set’ your body clock and you’ll find yourself getting sleepy at about the same time every night.
    Don’t ignore tiredness. Go to bed when your body tells you it’s ready.
    Don’t go to bed if you don’t feel tired. You will only reinforce bad habits such as lying awake.
    Get enough early morning sunshine. Exposure to light during early waking hours helps to set your body clock.
Improve your sleeping environment
Good sleep is more likely if your bedroom feels restful and comfortable. Suggestions include:
    Invest in a mattress that is neither too hard nor too soft.
    Make sure the room is at the right temperature.
    Ensure the room is dark enough.
    If you can’t control noise (such as barking dogs or loud neighbours), buy a pair of earplugs.
    Use your bedroom only for sleeping and intimacy. If you treat your bed like a second lounge room – for watching television or talking to friends on the phone, for example – your mind will associate your bedroom with activity.
Avoid drugs
Some people resort to medications or ‘social drugs’ in the mistaken belief that sleep will be more likely. Common pitfalls include:
    Cigarettes – many smokers claim that cigarettes help them relax, yet nicotine is a stimulant. The side effects, including accelerated heart rate and increased blood pressure, are likely to keep you awake for longer.
    Alcohol – alcohol is a depressant drug, which means it slows the workings of the nervous system. Drinking before bed may help you doze off but, since alcohol disturbs the rhythm of sleep patterns, you won’t feel refreshed in the morning. Other drawbacks include waking frequently to go to the toilet and hangovers.
    Sleeping pills – drawbacks include daytime sleepiness, failure to address the causes of sleeping problems, and the ‘rebound’ effect – after a stint of using sleeping pills, falling asleep without them tends to be even harder. These drugs should only be used as a temporary last resort and under strict medical advice.
Relax your mind
Insomnia is often caused by worrying. Suggestions include:
    If you are a chronic bedtime worrier, try scheduling a half hour of ‘worry time’ well before bed. Once you retire, remind yourself that you’ve already done your worrying for the day.
    Try relaxation exercises. You could consciously relax every part of your body, starting with your toes and working up to your scalp. Or you could think of a restful scene, concentrate on the rhythmic rise and fall of your breathing, or focus on a mantra (repeating a word or phrase constantly)
General suggestions
Other lifestyle adjustments that may help improve your sleep include:
    Exercise every day, but not close to bedtime and try not to overheat yourself – your body needs time to wind down.
    Try not to engage in mentally stimulating activities close to bedtime. Use the last hour or so before sleep to relax your mind.
    Don’t take afternoon naps.
    Avoid caffeinated drinks (like tea, coffee, cola or chocolate) close to bedtime. Instead, have a warm, milky drink, since milk contains a sleep-enhancing amino acid.
    Take a warm bath.
    Turn your alarm clock to the wall. Watching the minutes tick by is a sure way to keep yourself awake.
    If you can’t fall asleep within a reasonable amount of time, get out of bed and do something else for half an hour or so, such as reading a book.
    If you have tried and failed to improve your sleep, you may like to consider professional help. See your doctor for information and referral.