A sleep disorder refers to any condition that affects the quality, timing, or duration of sleep, leading to daytime distress and impairment in functioning. These disorders can manifest in various ways, such as difficulty falling asleep or staying asleep, insomnia, pauses in breathing during sleep, sleep apnea, excessive daytime sleepiness, narcolepsy, or involuntary movements during rest, restless leg syndrome. Sleep disorders can significantly impact overall health and quality of life by causing fatigue, mood disturbances, and increased risk of other health issues.