<unk>  is one of the four types of shock, caused by a physical obstruction in the flow of blood. Obstruction can occur at the level of the great vessels or the heart itself. Causes include pulmonary embolism, cardiac tamponade, and tension pneumothorax. These are all life-threatening. Symptoms may include shortness of breath, weakness, or altered mental status. Low blood pressure and tachycardia are often seen in shock. Other symptoms depend on the underlying cause. The physiology of<unk>  is similar to cardiogenic shock. In both types, the heart's output of blood (cardiac output) is decreased. This causes a back-up of blood into the veins entering the right atrium. Jugular venous distension can be observed in the neck. This finding can be seen in<unk>  and cardiogenic shock. With the decrease cardiac output, blood flow to vital tissues is decreased. Poor perfusion to organs leads to shock. Due to these similarities, some sources place<unk>  under the category of cardiogenic shock. However, it is important to distinguish between the two types, because treatment is different. In cardiogenic shock, the problem is in the function of the heart itself. In<unk> , the underlying problem is not the pump. Rather, the input into the heart (venous return) is decreased or the pressure against which the heart is pumping (afterload) is higher than normal. Treating the underlying cause can reverse the shock. For example, tension pneumothorax needs rapid needle decompression. This decreases the pressure in the chest. Blood flow to and from the heart is restored, and shock resolves. __TOC__
Obstructive shock
Distributive shock
Hypovolemic shock
Cryptic shock
Neurogenic shock
Vasodilatory shock
Septic shock
Cardiogenic shock