Breathing difficulty while lying down is an abnormal condition in which a person must keep the head raised (by sitting or standing) to be able to breathe deeply or comfortably.
A specific type of breathing difficulty while lying down is paroxysmal nocturnal dyspnea. This condition causes a person to wake up suddenly during the night feeling short of breath.
Orthopnea
Hypernea
Dyspnea
Myxedema
Apnea
Palpitation
Chest pain
Chest pain  