In addition to differentially diagnosing Pulmonary hypertension, the NP and interdisciplinary team must accurately classify the state of Pulmonary hypertension disease progression. The clinical classification of Pulmonary hypertension has undergone a series of revisions since first proposed in 1978 by the World Health Organization (WHO). During 2008, at the 4th World Symposium on Pulmonary hypertension, which convened in Dana Point, California, experts proposed modifications to the previous classifications. Currently, there are 5 clinical categories of Pulmonary hypertension. summarizes the 2008 clinical classification of Pulmonary hypertension.