<prompt> Answer this question truthfullyWhat is secondary pulmonary hypertension and what are some of the causes related to lung disease that can lead to its development?  <response>: <reason> Secondary pulmonary hypertension is a condition characterized by increased blood pressure in the pulmonary arteries. It can arise as a result of various underlying conditions related to lung disease, such as damage or inflammation of lung parenchyma e.g. COPD Interstitial lung disease or hypoxic pulmonary vasoconstriction e.g. obstructive sleep apnea, high altitude. Other possible causes include chronic thromboembolic disease and left heart disease. 