The diagnosis and management of aortic dissection. Aortic dissection is a severe disease. Most untreated patients with types I and II (proximal) dissection and over half of those with type III (distal) dissection die within 1 year. Most of the deaths occur within 2 weeks and are caused by rupture, aortic insufficiency, and branch vessel obstruction. Aortic dissection is suspected in patients with anterior chest and back pain that progresses downward. Diagnosis is confirmed by computed tomography, aortography, or echocardiography. Appropriate medical treatment and corrective surgery, including total aortic replacement, performed in the acute and chronic stages, are now successful in over 90% of the cases; long-term results of treatment are steadily improving and are expected to exceed 50% at 10 years. The keys to a successful outcome are being aware of the symptoms of dissection, early diagnosis, and prompt application of appropriate treatment; diligent follow-up includes controlling blood pressure, decreasing the velocity of left ventricular contraction, monitoring the size of the residual aorta, and taking appropriate action if redissection, aneurysmal formation, or rupture occurs. 