Clinical Research Directory

Inclusion Criteria: * 1\. Age 18 years or older 2\. Patients with pre-capillary pulmonary hypertension, Group 1 PAH, Group 3 PH associated with lung disease/hypoxia, Group 4 chronic thromboembolic pulmonary hypertension (CTEPH) or other pulmonary artery obstructions, and Group 5 PH with unclear or multifactorial mechanisms. 3\. Diagnosis of pulmonary hypertension based on RHC when available, or high echocardiographic probability/clinician diagnosis of PH when RHC is not available. 4\. Availability of baseline clinical assessment at or near the time of diagnosis or first PH-unit presentation. 5\. Ability to provide an approximate date or month/year of first PH-related symptom. 6\. Willingness to participate and provide informed consent. Exclusion Criteria: * 1\. Inability to provide reliable information about symptom onset and no alternative documentation in the medical record. 2\. Incomplete baseline data preventing classification of disease severity. 3. Post-capillary pulmonary hypertension due to left heart disease (Group 2 PH). 4\. Acute pulmonary embolism as the sole acute cause of transient pulmonary pressure elevation at presentation. 5\. Severe acute illness, cognitive impairment, or communication barrier preventing questionnaire completion. 6\. Refusal to participate. 7. Optional exclusion according to committee preference: patients with isolated post-capillary PH due to left heart disease may be excluded if the aim is to focus on PAH/pre-capillary PH.