With normal blood pressure and heart and lungs, why does one wake up breathless during sleep.?

Heart or lung diseas: Waking up breathless during sleep is always a serious medical problem that involves either the heart or lungs. It is never normal. The only instance in which someone would wake up breathless and have no medical problem is if they were having a nightmare or night terror. Otherwise, this condition should always be taken very seriously since it is caused either by serious heart or lung disease.

Many reasons: If someone is obese or has some type of airway obstruction, this may can cause what is called obstructive sleep apnea, also gastric content regurgitation that goes to the lungs due gastroesophageal reflux may cause someone to wake up catching their breath.