Acute, transient insomnia (<4 weeks)
Recent or recurring stress
Change in sleeping environment
Acute illness or injury
New medications (see Table 2)
Jet lag or shift change
Chronic insomnia (> 4 weeks)
Difficulty staying asleep
	Medications (see Table 2)
	Drug or alcohol use
	Psychiatric disorders (e.g., depression, anxiety)
	Medical disorders (see Table 3)
	Sleep-disordered breathing (e.g., sleep apnea)
	Nocturnal myoclonus
Difficulty falling asleep
	Poor sleep hygiene
	Conditioned insomnia (behavioral conditioning)
	Restless legs syndrome
	Circadian rhythm disorder
	Advanced sleep-phase syndrome
	Delayed sleep-phase syndrome