alertness alertness alertness is the state of active attention by high sensory awareness such as being watchful and prompt to meet danger or emergency, or being quick to perceive and act. it is related to psychology as well as to physiology. a lack of alertness is a symptom of a number of conditions, including narcolepsy, attention deficit disorder, chronic fatigue syndrome, depression, addison's disease, or sleep deprivation. pronounced lack of alertness can be graded as an altered level of consciousness. states with low levels of alertness include drowsiness. part of a series onmindfulness buddhism buddhist meditation sati anussati sampajañña satipatthana anapanasati mental noting appamāda vipassanā zen psychology mindfulness-based stress reduction mindfulness-based cognitive therapy mindfulness-based pain management acceptance and commitment therapy dialectical behavior therapy mode deactivation therapy morita therapy hakomi therapy mindfulness (journal) other buddhism and psychology mindful yoga similar concepts wakefulness attention alertness prudence conscientiousness awareness observation choiceless awareness category the word is formed from "alert", which comes from the italian "all'erta" (on the watch, literally, on the height; 1618). wakefulness refers mainly to differences between the sleep and the wake state, including for modulation or stimulation of these pathways, and vigilance refers to sustained alertness and concentration but both terms are sometimes used synonymously with alertness. physiological aspects domenico tintoretto, allegory of vigilance people who have to be alert during their jobs, such as air traffic controllers or pilots, often face challenges maintaining their alertness. research shows that for people "...engaged in attention-intensive and monotonous tasks, retaining a constant level of alertness is rare if not impossible." if people employed in safety-related or transportation jobs have lapses in alertness, this "may lead to severe consequences in occupations ranging from air traffic control to monitoring of nuclear power plants." biological pathways