Pulmonary hypertension syndrome (PHS) has always been of significant importance related to cardiovascular diseases. The PHS is one of the major reasons for the high morbidity and mortality in broilers negatively impacting the broiler farming industry. In this study samples from lungs and blood of broilers with enlarged and normal abdomen were collected and fluorescence quantification, immunohistochemistry and histopathology of the selected organs were done to diagnose this disease in broilers. Clinically, it was observed that morbid broilers were depressed, dyspneic, right heart hypertrophied, right ventricle to total ventricle volume (RV/TV) was greater than 0.25 and abdomen was enlarged having yellowish fluid. The diagnosis of PHS was confirmed by the RV/TV and clinical symptoms whereas, the histopathological observations revealed that with age the pulmonary vascular density decreased, lumen of the pulmonary vessels was narrowed and the middle layer of pulmonary vessels was thickened. Hematoxylin and Eosin (HE) staining of the selected samples was done. It was found that age increased in greater interstitial spaces in the lungs of PHS broilers along with inflammatory cells infiltrating the lungs. Results of fluorescence quantification and immunohistochemistry revealed that all types of PDK (PDK1, PDK2, PDK3, PDK4) exhibited significant upregulation in the lungs of broilers with PHS onset and PDK4 was significantly expressed on pulmonary vessels. Therefore, it was concluded that PHS leads to remodeling of the pulmonary vasculature leading to ascites and PDK plays an important role in the progression of PHS.