A tendency to become unusually sleepy or doze during waking activities. It is a symptom with multiple possible causes, not a diagnosis and not the same as simply feeling fatigued.
Excessive daytime sleepiness refers to difficulty maintaining wakefulness or an increased tendency to fall asleep during the day. It differs from fatigue, which may feel like low energy, exhaustion, or reduced capacity without an actual tendency to doze. Possible contributors include insufficient sleep opportunity, sleep fragmentation, sleep-disordered breathing, circadian disruption, medications, medical conditions, mood disorders, and other causes. The symptom does not identify its own mechanism. The Epworth Sleepiness Scale is a widely used self-report instrument for estimating the likelihood of dozing in common situations. It measures daytime sleepiness; it does not diagnose obstructive sleep apnea, insomnia, narcolepsy, or another underlying condition. The ESS is copyrighted and requires permission or licensing for use. Sleepgenic uses daytime sleepiness as a lived-outcome signal that can strengthen the significance of a recurring wearable pattern. It does not infer its presence from a sleep score alone and does not substitute wearable data for clinical evaluation.
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