<prompt> Most common cause of Aortic dissection -HypertensionDMTraumaMarfan syndrome  <response>: More than 90 of dissections occur in men between the age of 40 and 60 with antecedent hypertension. Other causes of dissection.Marfan syndrome causing cystic medial necrosis second most common.Ehlers - Danlos syndrome.Inflammatory aortitis Takayasus disease, Giant cell arteritis.Coarctation of aorta.Normal woman during third trimester of pregnancy.Congenital bicuspid aortic valve. 