An apparatus for use in diagnosing the presence of obstructive sleep apnea (OSA) in a patient includes a sensing module structured to measure a parameter indicative of a tremor in the patient's neck, tongue and/or throat muscles while the patient is awake, the parameter not being airflow through the patient's airway. The sensing module generates one or more electrical signals based on the measured parameter. The apparatus also includes a processor operatively coupled to the sensing module, the processor being structured to receive the one or more electrical signals, perform an analysis of the one or more electrical signals, and based on the analysis determine whether the tremor has a frequency in at least one predetermined frequency range that is indicative of OSA.