Inability to sleep, in the absence of external impediments, such as noise, a bright light, etc., during the period when sleep should normally occur; may vary in degree from restlessness or disturbed slumber to a curtailment of the normal length of sleep or to absolute wakefulness. SYN: sleeplessness. [L. fr. in- priv. + somnus, sleep]
- conditioned i. a form of i. resulting from conditioned behaviors that are incompatible with sleep, e.g., each time a person walks into his bedroom, his first thought is that he is not going to be able to sleep.
- subjective i. a condition characterized by the subjective experience of greatly reduced sleep, in the context of relatively normal physiologic measures of sleep.
* * *
in·som·nia in-'säm-nē-ə n prolonged and usu. abnormal inability to obtain adequate sleep called also agrypnia
* * *
n.
inability to fall asleep or to remain asleep for an adequate length of time, so that tiredness is virtually permanent. Insomnia may be associated with disease, particularly if there are painful symptoms, but is more often caused by worry.
* * *
in·som·nia (in-somґne-ə) [in-2 + somn- + -ia] inability to sleep; abnormal wakefulness.Medical dictionary. 2011.