Acute dissection is the most common life threatening condition of the aorta affecting 5-30 per million people per year [1].Left untreated, the majority of patients with dissections involving the ascending aorta will die within days of an acute episode [2].Patients presenting with descending thoracic aortic dissections seem to fare better, with one in ten patients dying before leaving hospital. Ultimately, these patients are at risk of aortic rupture with nearly 20% of these patients requiring some form of surgical or endovascular intervention [3].Judicious medical, surgical and endovascular management of this condition aims to reduce propagation of the dissection plane and concomitant branch vessel compromise, halt aortic expansion and prevent fatal aortic rupture.Early recognition of these disease entities in conjunction with urgent and pertinent management is the key to a successful outcome in these patients. DEFINITIONAcute dissection results from sudden tear of the intima and separation of the layers within the aortic wall. This results in the longitudinal and spiralling flow of pulsatile blood between the inner and outer layers of the tunica media propagating the extent of dissection with the variable formation of both true and false lumina Fig. (1).Dynamic obstruction of the true lumen by the expanding false lumen will result in organ ischaemia unless spontaneous and adequate fenestration of the distal intimal flap does not occur [4]. Often these fenestrations can be found at the site of branched vessel ostia leaving the native aorta to supply target organs. Disruption of the intima here, often leads to invagination of the intima within the target vessel with static obstruction of laminar blood flow in the true lumen and the high probability of arterial thrombosis and end organ infarction. ACUTE AORTIC SYNDROMEIn addition to aortic dissections, two further aortic pathologies often encountered are penetrating aortic ulcers and intramural haematomas. Both these conditions are found in a more elderly hypertensive population in whom women predominate. Grouped together, the three pathologies have been coined the acute aortic syndrome and are representative of Fig. (1). Arch aortogram demonstrating true lumen collapse (T) and extraluminal expansion of false lumen (F) in a Stanford type B aortic dissection. The main communication between the true and the false lumens occurs immediately beyond the left subclavian artery (C).degenerative changes encountered in the atherosclerotic aortic wall. In comparison to acute aortic dissection, visceral and limb ischaemia do not appear to be a prevalent feature of either penetrating ulcers or intramural haematomas.