Daytime sleepiness
May be underestimated due to chronic nature, insidious onset
Loud snoring, gasping, interruptions in breathing while sleeping
Morning headaches
Usually bifrontal, squeezing
Possibly secondary to hypercapnia, vasodilation, increased intracranial pressure, and impaired sleep quality
May be underestimated due to chronic nature, insidious onset
Usually bifrontal, squeezing
Possibly secondary to hypercapnia, vasodilation, increased intracranial pressure, and impaired sleep quality
Obstructive sleep apnea
Excessive daytime sleepiness
Sick sinus syndrome
Insufficient sleep - shift work, underlying comorbidity, medication affects
Pulmonary hypertension 
Sleep disorders - circadian rhythm sleep-wake disorder, narcolepsy
Pulmonary hypertension
Sleep related movement disorder - restless legs syndrome, periodic limb movement disorder