What are primary and secondary pulmonary hypertension?
In the conventional classification, pulmonary hypertension, which is also called pulmonary arterial hypertension, is divided into two main categories; 1) primary pulmonary hypertension (not caused by any other disease or condition); and 2) secondary pulmonary hypertension (caused by another underlying condition). Secondary pulmonary hypertension is much more common than primary pulmonary hypertension. A newer classification of this condition is based on the main underlying cause of pulmonary hypertension. This system classifies the condition based on whether it is due to: • left sided heart disease, • lung disease, • blood clots, • constriction of arteries due to any reasons (including primary pulmonary hypertension), and • obstruction from outside of blood vessel (for example from diseases of the chest wall compressing the blood vessels). What causes pulmonary hypertension? Pulmonary hypertension can be caused by diseases of the heart and the lungs, such as: • chronic obstructive pulm
