Which condition is often associated with excessive daytime sleepiness?

Excessive daytime sleepiness is frequently linked to obstructive sleep apnea (OSA). In OSA, individuals experience repeated episodes of partial or complete obstruction of the upper airway during sleep, leading to disrupted breathing and frequent awakenings. This interruption in sleep not only reduces the overall quality of rest but also contributes to a significant amount of daytime fatigue and sleepiness, hindering concentration and overall functioning.

While conditions like insomnia, restless leg syndrome, and parasomnias can also impact sleep quality, they do not typically result in excessive daytime sleepiness to the same extent as obstructive sleep apnea. Insomnia primarily involves difficulty in falling or staying asleep, while restless leg syndrome provides uncomfortable sensations that cause sleep interruptions, but they are less directly related to the substantial sleep-reduction episodes seen in OSA. Similarly, parasomnias involve abnormal sleep behaviors but do not consistently lead to the characteristic daytime sleepiness associated with obstructive sleep apnea. Therefore, obstructive sleep apnea stands out as the condition most closely connected with excessive daytime sleepiness.