Clinical Reasoning: A 27-Year-Old Male Patient Presenting With Excessive Daytime Sleepiness of Subacute Onset

The evaluation of excessive daytime sleepiness can be challenging. We present a 27-year-old male patient with severe somnolence, nocturnal sleep fragmentation, and a frequent need for daytime naps persisting for more than 18 months. This case highlights a systematic approach to diagnosing excessive daytime sleepiness, emphasizing the identification of key clinical features, the use of targeted diagnostic tests, and the importance of considering alternative etiologies when typical markers are absent.