Are Hiatal Hernias Similar To Diaphragmatic Hernias? I'm 34, 5'10'',

Are hiatal hernias similar to diaphragmatic hernias? I'm 34, 5'10'', 200lbs, 2 pack a week smoker for past 4 years. I have heartbearn, but never difficulty swallowing saliva until after I was in a car accident (rear ended). Can the seatbealt pressure on my xiphoid process cause a hiatal or diaphragmatic hernia? I did the barium test and the Dr. said diaphragmatic hernia, but didn't say if it was caused by the accident.