Final answer:
Key symptoms of obstructive sleep apnea include daytime sleepiness, insomnia, and morning headaches (a,c,d). Bradycardia is not commonly associated with OSA. These symptoms arise due to the repeated interruptions in breathing during sleep.
Step-by-step explanation:
The clinical manifestations associated with obstructive sleep apnea (OSA) are varied, but some of the key symptoms include daytime sleepiness, insomnia, and morning headaches. Patients with OSA often experience cessation of breathing during sleep that leads to a fragmented, poor quality of sleep, resulting in significant daytime drowsiness. Insomnia can also be a symptom, often due to the inability to stay asleep because of the repeated awakenings from the breathing interruptions.
Morning headaches are another common manifestation, likely due to low oxygen levels and fluctuating carbon dioxide levels in the blood during apneic events. Meanwhile, bradycardia is not typically associated with OSA; in fact, sleep apnea more commonly can cause an increase in heart rate or arrhythmias rather than a slowing down of the heart rate.