The basic investigation should include, in addition to the assessment of vital signs, a thorough medical history and careful clinical examination. A broad differential diagnosis is required to identify or rule out the most common causes of dyspnea. About two-thirds of cases of chronic dyspnea are caused by heart or lung diseases.
Based on the overall clinical question and the findings from Step 1, targeted examinations are performed. If a diagnosis cannot be established after investigations according to Steps 1 and 2, early contact should be made with a specialist center.
At this stage, the patient undergoes further evaluation to diagnose and treat PAH and CTEPH. All follow-up and medication adjustments are managed through the specialist center.