There are a number of different sleep disorders that afflict a great number of people. The following is a list of various sleep disorders that can be experienced: One is able to distinguish between these disorders by the specific symptoms that he/she experiences. The following is a general and simplified description of each sleep disorder.
 

                                             Primary Insomnia

The major complaint for this disorder is the inability to initiate or maintain sleep, or non-restorative sleep (sleep that does not refresh the individual when they awaken).  This sleep difficulty causes a great deal of distress in the individual's level of functioning in social, occupational and other important areas.  Furthermore, this difficulty does not necessarily happen when the individual is experiencing other types of sleep disorders. In addition, the difficulty falling or maintaining sleep does not necessarily occur when another mental health disorder is coexistent (i.e. depression).   Finally, this disturbance is not as a direct result of the physiological effects of a substance (alcohol or drug) or a medical condition.

                                          Primary Hypersomnia

The major complaint for this disorder is excessive sleepiness.  This sleepiness can best be defined when there is too much sleeping (what is beyond the necessary amount of sleep needed) or sleeping during the day (occurs almost daily).  As was the case with insomnia, this sleepiness causes much distress in the individual's  level of functioning in social, occupational or other significant areas of functioning.  It is worth noting that the insomnia or other sleep disorders are not necessarily the cause of this excessive sleepiness. Furthermore, this hypersomnia does not necessarily occur while another mental health disorder coexists.  Finally, and as stated with insomnia, the hypersomnia does not happen because of the physiological effects of a substance (drug or alcohol) or a medical condition.

                                                 Narcolepsy

When an individual experiences narcolepsy, he/she is attacked by an irresistible sleep during the daytime hours. In addition, one of two of the following must also be present:

Once again, it is worth noting that narcolepsy is not due to the physiological effects of a substance (alcohol or drug) ot a medical condition.

                                  Breathing Related Sleep Disorder

This disorder should be self explanatory. There is a disruption of sleep in the individual experiencing this disorder, which will lead to either insomnia or significant sleepiness. This disruption is caused by a breathing condition while the person is sleeping (i.e. sleep apnea, where the individual does not get enough air while breathing during sleep and therefore awakens on numerous occasions in need of air). As with other sleep disorders, this disorder is not caused by a mental health disorder or a a result of physiological effects of a substance (alcohol or drug) or medical condition.

                                  Circadian Rhythm Sleep Disorder

During this disorder, an individual experiences a disruption in sleep, which leads to insomnia or excessive sleepiness.  This disruption is due to a mismatch in the person's sleep-wake cycle because of his/her environment (i.e. firefighters being woken up repeatedly while sleeping).  This disturbance causes a great deal of impairment in the person's level of functioning in social, occupational or other significant levels of functioning.   This disturbance does not occur while another sleep or mental health disorder is present.  Furthermore, the disturbance is not because of the physiological effects of substances (drugs or alcohol).
It is worth noting that 3 types of this disorder exists:

                                             Nightmare Disorder

During this disorder, there are numerous awakening periods after the individual has experienced significantly terrifying dreams. These dreams are usually about surviving, security or related to feelings of self-worth,  Once the individual is awakened, however, he/she is quickly reoriented to their environment.  The experience of these dreams and nightmares cause impairments in the person's level of functioning in social, occupational and other important areas.  Finally, and as true with other sleep disorders, the nightmares do not happen while other mental health or sleep disorders exist. In addition, they are not induced by the physiological effects of substances (drugs or alcohol).

                                           Sleep Terror Disorder

The person who experiences this disorder wakes up from sleep repeatedly during the course of their sleep.  He/she experiences significant fear and other signs of autonomic responses such as rapid heart rate, increased rate of breathing, and sweatiness. while the person is experiencing the episode, efforts of others to comfort the individual go without much effect. The person typically forgets what he/she was dreaming about and is unable to recall the dream in any detailed fashion.  This disorder causes disturbance in the daily social, occupational and other significant areas of functioning.  This disorder is not caused by substances (drug or alcohol) or a medical condition.

                                          Sleepwalking Disorder

Sleepwalking disorder is simply what it sounds. During this disorder, the person rises from his/her bed repeatedly and walks about his/her environment. This person is completely unresponsive to others and their attempt to awaken him/her. they often times have a blank face and stare while walking.   Once the person is awakened (whether it is the next day or that same night), he/she remembers nothing of the sleepwalking episode.  Even though initially there may be some confusion right after the awakening, the person experiences no impairments in mental activities.   Once again, this disorder causes impairments in social, occupational and other important levels of functioning.  In addition, this disturbance is not caused by the physiological effects of substances (alcohol or drugs) or a medical condition.