<prompt> pulmonary hypeension is caused by all except ?hyperventilationmorbid obesityfenfluraminehigh altitude  <response>: DEFINATIONS Pulmonary hypeension PH is haemodynamic and pathophysiological condition defined as mean pulmonary aery pressure 25 mmHg at rest by Right hea CatheterizationRHC. Pulmonary aerial hypeension PAH is a clinical condition characterized by the presence of pre-capillary PH in absence of other causes of pre-capillary PH such as PH due to lung diseases, chronic thromboembolic PH, or other rare diseases Clinical Presentation Non specific leading to delayed diagnosis Symptoms: dyspnea most common, exercise intolerance, fatigue, substernal chest pain, and palpitations. Symptoms of right hea failure include exeional dizziness, syncope, chest pain, lower extremity swelling, increased abdominal gih ascites, and hoarseness impingement of recurrent laryngeal nerve by enlarging pulmonary aery. Assess for exposure to anorectic drugs and symptoms of underlying diseases , family history of PH Types Group 1 PAH pulmonary aerial hypeension Group 2 PH left hea disease Group 3 PH lung disease Group 4 PH thromboembolic disease Group 5 PH multifactorial ref : harrisons 21st ed 