Most common cause of Aoic dissection ?

Ans. is 'a' i.e., Hypeensiono More than 90% of dissections occur in men between the age of 40 and 60 with antecedent hypeension. Other causes of dissection.o Marfan syndrome causing cystic medial necrosis (second most common).o Ehlers - Danlos syndrome.o Inflammatory aoitis --> Takayasu's disease, Giant cell aeritis.o Coarctation of aoa.o Normal woman during third trimester of pregnancy.o Congenital bicuspid aoic valve.