What Is Insomnia ?

A sleep disorder is a disruptive pattern of sleep that may include difficulty falling or staying asleep, falling asleep at inappropriate times, excessive total sleep time, or abnormal behaviors associated with sleep.

More than 100 different disorders of sleeping and waking have been identified. They can be grouped within 4 main categories: problems with staying and falling asleep, problems with staying awake, problems with adhering to a regular sleep schedule, and sleep disruptive behaviors.

PROBLEMS WITH STAYING AND FALLING ASLEEP

Insomnia includes any combination of difficulty with falling asleep, staying asleep, intermittent wakefulness, and early-morning awakening. Episodes may be transient, short-term (lasting 2 to 3 weeks), or chronic. Illness, depression, anxiety, stress, poor sleeping environment (e.g., noise or too much light), caffeine, abuse of alcohol, medications, heavy smoking, physical discomfort, daytime napping, certain medical conditions, and other counterproductive sleep habits such as early bedtimes, and excessive time spent awake in bed are common factors associated with insomnia.

There are three types of insomnia:

• Transient, or mild, insomnia - sleep difficulties that last for a few days; there is little or no evidence of impairment of functioning during the day
  
  

• Short-term, or moderate, insomnia - sleep difficulties that last for less than a month, that mildly affect functioning during the day, together with feelings of irritability and fatigue
  
  

• Chronic, or severe, insomnia - sleep difficulties that last for more than a month, that severely impair functioning during the day, and cause strong feelings of restlessness, irritability, anxiety, and fatigue
  
  

Insomnia can have physical and psychological effects. The consequences of insomnia include:

• Impaired mental functioning. Insomnia can affect concentration and memory, and can affect one's ability to perform daily tasks.
  
  

• Accidents. Insomnia endangers public safety by contributing to traffic and industrial accidents. Various studies have shown that fatigue plays a major role in automobile and machinery accidents. As many as 100,000 automobile accidents, accounting for 1,500 deaths, are caused by sleepiness.
  
  

• Stress and depression. Insomnia increases the activity of the hormones and pathways in the brain that cause stress, and changes in sleeping patterns have been shown to have significant affects on mood. Ongoing insomnia may be a sign of anxiety and depression.
  
  

• Heart disease. One study reported that people with chronic insomnia had signs of heart and nervous system activity that might put them at risk for heart disease.
  
  

• Headaches. Headaches that occur during the night or early in the morning may be related to a sleep disorder.
  
  

• Economic effects. Insomnia costs the U.S. an estimated $100 billion each year in medical costs and decreased productivity.
  
  

Disorders of excessive sleepiness are called hypersomnias. These include:

• Sleep apnea

• Narcolepsy

• Restless leg syndrome

• Obstructive sleep apnea

• Central sleep apnea

• Idiopathic hypersomnia

• Respiratory muscle weakness associated sleep disorder

Sleep apnea more commonly affects obese, people but it may affect others with short necks or a small jaw. The disorder causes breathing to stop intermittently during sleep resulting in people being awakened repeatedly such that they have difficulty achieving prolonged deep sleep and results in excessive daytime sleepiness. Narcolepsy is a condition of daytime sleep attacks as well as other features which may include sleep paralysis and hypnagogic hallucinations. Sleep attacks occur despite adequate sleep at night. Restless leg syndrome is a condition of periodic lower-leg movements during sleep with associated daytime sleepiness, or complaints of insomnia.

PROBLEMS WITH ADHERING TO A REGULAR SLEEP SCHEDULE

Problems may also occur with maintaining a consistent sleep and wake schedule as a result of disruptions of normal times of sleeping and wakefulness. This occurs when traveling between times zones and with shift workers on rotating schedules, particularly with nighttime workers.

These disorders include:

• Sleep state misperception (the person actually sleeps a different amount than they think they do)

• Shift work sleep disorder

• Natural short sleeper (the person sleeps less hours than "normal" but suffers no ill effects)

• Chronic time zone change syndrome

• Irregular sleep-wake syndrome

SLEEP DISRUPTIVE BEHAVIORS

Abnormal behaviors during sleep are called parasomnias, and are fairly common in children. They include:

• Sleep terror disorder

• Sleep walking

• REM behavior disorder (a type of psychosis can develop related to lack of REM sleep and lack of dreaming)

Sleep terror disorder is an abrupt awakening from sleep with fear, sweating, rapid heart rate, and confusion. Sleep walking is not remembered by the person doing it and affects children 2 to 12 years old. In adults, it may also be caused by an organic brain syndrome, reactions to drugs, psychopathology and medical conditions.