Shock is a pathological state of global tissue hypoperfusion, due to an imbalance of oxygen delivery and demand of the tissues. This leads to anaerobic metabolism of the cells, and thus production of lactate and cellular dysfunction. Shock can be classified into four major types, based on the mechanism of circulatory collapse—hypovolemic, cardiogenic, obstructive, and distributive shock. Early recognition and prompt treatment are essential for improved outcomes in shock. Adequate fluid resuscitation, appropriate use of vasopressors to maintain tissue perfusion, and treatment of the underlying cause are essential.