Insomnia is the perception or complaint of inadequate or poor-
quality sleep because of one or more of the following: Insomnia
is not defined by the number of hours of sleep a person gets or
how long it takes to fall asleep. Individuals vary normally in
their need for, and their satisfaction with, sleep. Insomnia may
cause problems during the day, such as tiredness, a lack of
energy, difficulty concentrating, and irritability. Insomnia can
be classified as transient (short term), intermittent (on and
off), and chronic (constant). Insomnia lasting from a single
night to a few weeks is referred to as transient. If episodes of
transient insomnia occur from time to time, the insomnia is said
to be intermittent. Insomnia is considered to be chronic if it
occurs on most nights and lasts a month or more. Certain
conditions seem to make individuals more likely to experience
insomnia. Examples of these conditions include: If other
conditions (such as stress, anxiety, a medical problem, or the
use of certain medications