Patient presents with excessive daytime sleepiness, fatigue, and complaints of difficulty maintaining wakefulness.  Symptoms include prolonged sleep episodes at night, sometimes exceeding 10 hours, and still experiencing daytime sleep attacks.  Patient reports feeling unrefreshed upon awakening.  Symptoms impact daily activities such as work productivity and social functioning.  Differential diagnosis includes obstructive sleep apnea, narcolepsy, idiopathic hypersomnia, circadian rhythm sleep disorders, and insufficient sleep syndrome.  Objective findings may include slow reaction times and impaired cognitive function during clinical assessment.  Patient denies use of sedating medications.  Polysomnography and Multiple Sleep Latency Test (MSLT) ordered to evaluate for underlying sleep disorders.  Consider referral to sleep specialist for further evaluation and management.  Treatment plan may include behavioral modifications such as sleep hygiene education, strategic napping, and regular exercise.  Pharmacological interventions may be considered if behavioral interventions are insufficient, pending results of sleep studies.  ICD-10 code G47.1, Excessive daytime sleepiness, assigned.  Patient education provided regarding sleep disorders, importance of adherence to treatment plan, and potential side effects of medications.  Follow-up appointment scheduled to review sleep study results and discuss management options.