**Abstract**

Obstructive sleep apnea (OSA) is often confused with the clinical symptoms of other adult/pediatric medical conditions and neurological disorders. Since OSA affects all systems in the body, it is important to establish a correct diagnosis. The first step in the evaluation of a patient with a sleep disorder is to identify the primary symptom. A detailed history of the sleep and wakefulness cycles constitutes the second step. This is followed by the medical history of the patient; a list of previously used medications; family history; detailed information about school, work, family, and social life; and a physical exam of bodily systems. Relevant laboratory tests are performed for differential diagnosis. Polysomnography (PSG) is a golden standard diagnostic method that records electrophysiological signals used for sleep physiology and diseases. PSG is an indispensable method in the diagnosis of OSA.

**Keywords:** anamnesis, symptoms, physical examination, electrophysiology, PSG, sleep breathing disorders, snoring and OSA
