Sleep disturbance Insomnia 2011-06-07T06:14:22Z Inability to sleep The individual subjectively reports the inability to sleep, which may manifest as prolonged sleep latency, frequent awakenings, or premature morning awakening. This phenomenon is often linked or associated with distress, reduced daytime functioning, or dissatisfaction with sleep. Difficulty staying or falling asleep HP:0100785 SNOMEDCT_US:193462001 UMLS:C0917801 Persistent difficulty in starting or maintaining sleep, or waking up earlier than desired, despite having adequate opportunities and conditions for sleep.