Sleepiness

Somnolence (or "drowsiness", or "hypersomnia") is a state of near-sleep, a strong desire for sleep, or sleeping unusually long periods. It has two distinct meanings, referring both to the usual state preceding falling asleep, and the chronic condition referring to being in that state independent of a circadian rhythm. The disorder characterised by the latter condition is most commonly associated with users of prescription hypnotics, such as Mirtazapine or Zolpidem.

It is considered a lesser impairment of consciousness than stupor or coma.

Associated conditions

 * sleep apnea, mostly due to obesity
 * narcolepsy
 * pharmaca
 * tranquilizers
 * hypnotics
 * some antipsychotics. For example: thioridazine but not haloperidol.
 * some analgesics
 * some antiepileptics
 * some antihistamines
 * generally many other agents with impact on central nervous system in sufficient doses


 * clinical depression, especially seasonal affective disorder or SAD
 * increased intracranial pressure
 * intracranial tumors
 * stroke
 * trauma to the brain
 * brain edema
 * any other intracranial bleeding such as due to ruptured aneurysm
 * hydrocephalus
 * encephalitis - (viral, bacterial or other agens)
 * and many others