Primary Sleep Disorders

In addition to the causes and conditions listed above, there are also a number of conditions that are associated with insomnia in the absence of another underlying condition. These are called primary sleep disorders, in which the sleep disorder is the main cause of insomnia. These conditions generally cause chronic or long-term insomnia. Some of the diseases are listed below:

* Idiopathic Insomnia (unknown cause) or childhood insomnia, which start early on in life and results in lifelong sleep problems. This may run in families.

* Central Sleep Apnea. This is a complex disorder. It can be the primary cause of the insomnia itself or it may be caused by other conditions, such as brain injury, heart failure, high altitude, and low oxygen levels.

* Restless leg syndrome (a condition associated with creeping sensations in the leg during sleep that are relieved by leg movement)

* Periodic limb movement disorder (a condition associated with involuntary repeated leg movement during sleep)

* Circadian rhythm disorders (disturbance of the biological clock) which are conditions with unusual timing of sleep (for example, going to sleep later and waking up late, or going to sleep very early and getting up very early).

* Sleep state misperception, in which the patient has a perception or feeling of not sleeping adequately, but there are no objective (polysomnographic or actigraphic) findings of any sleep disturbance.

* Insufficient sleep syndrome, in which the patient's sleep is insufficient because of environmental situations and lifestyle choices, such as sleeping in a bright or noisy room.

* Inadequate sleep hygiene, in which the individual has poor sleep or sleep preparation habits (described in the following treatment section.)

http://www.emedicinehealth.com/insomnia/page3_em.htm#Primary%20Sleep%20Disorders