Persistent daytime sleepiness can sometimes be linked to an underlying sleep disorder. Narcolepsy, obstructive sleep apnea, and shift work disorder are among the conditions associated with excessive sleepiness. Symptoms can affect alertness, daily routines, work performance, and quality of life. Armodafinil may be prescribed for adults with excessive sleepiness related to these conditions. Proper diagnosis is an important step before choosing an appropriate treatment approach.