Sleep disorders are very common and serious.  There are many causes of sleep disorders.  You can work with your team of doctors to diagnose your problem. 

The National Commission on Sleep Disorders Research estimates that 40 million Americans suffer from chronic sleep disorders and another 20 to 30 million experience sleep problems intermittently. And since sleep disorders increase with aging, those suffering from chronic sleep disorders are expected to rise to 79 million and those suffering from intermittent problems to increase to 40 million by 2010, as the U.S. population ages.   However, the vast majority of Americans with sleep disorders remain undiagnosed and under treated.

The National Institutes of Health define a sleep disorder as any difficulty related to sleeping, including:

• Difficulty falling or staying asleep
• Falling asleep at inappropriate times
• Excessive total sleep time
• Abnormal behaviors associated with sleep
• Sleep disorders can generally be grouped into categories such as:Lack of sleep (e.g., insomnia )
• Disturbed sleep (e.g., obstructive sleep apnea, periodic limb movements, and restless legs syndrome )
• Excessive sleep (e.g., narcolepsy and hypersomnia )
• Disturbed circadian rhythm (e.g. shift work sleep disorder and jet lag)

If you suspect that you may have a sleep disorder, discuss your symptoms with your primary care physician. 

The first steps towards getting a diagnosis will commonly include:

• A thorough description of symptoms.  Other family members play an important role here, since they can describe behaviors that the patient won't remember, such as snoring, limb movements, or sleepwalking.  
  
  
• Both a medical history and a psychological history.
  
  
• A physical exam. 
  
  
• A sleep questionnaire (Epworth Sleepiness Scale). The patient ranks whether certain situations make them sleepy and, if so, how sleepy.
  
  
• A sleep diary. Many doctors ask patients to keep a sleep diary for one or two weeks to record their sleep habits and daily routines.
  
  
• Tests to rule out other conditions.  These may include blood tests for thyroid levels, iron, and glucose, kidney and liver function tests and an EKG.

If insomnia is diagnosed your doctor may refer you to a specialist for psychological tests. Insomnia is frequently associated with mood or affective disorders.

If your doctor suspects that you have a sleep disorder, he or she may refer you to a sleep disorder clinic. A sleep specialist will review your symptoms and may suggest that you undergo a sleep study.  Tests include:

• Polysomnography (PSG). This test measures brain waves, eye movements, cardiac rhythms and other physical functions during sleep.  It usually requires an overnight stay at a sleep clinic for observation though portable equipment is available for home recording of a limited number of factors.
  
  
• Overnight oximetry. This test is used for patients with suspected obstructive sleep apnea to determine the oxygen level in the bloodstream during apnea episodes.
  
  
• Multiple sleep latency test (MSLT). This test measures the speed with which a patient falls asleep during a series of planned naps during the day and also measures the amount of REM sleep that occurs.
  
  
• Repeated test of sustained wakefulness (RTSW).  This test measures how long it takes for a patient to fall asleep by challenging his or her ability to stay awake. This is  also known as the "MWT" or maintenance of wakefulness test.