Pulmonary arterial hypertension (PAH) is a progressive and rare severe disease (prevalence of 15-50 per million) due to obstruction of small pulmonary arteries, leading to an increase in pulmonary artery pressure with the ultimate consequence right heart failure. Despite recent advances in therapeutic care, there is no cure and most patients die or require lung transplantation within 5 years of diagnosis. Currently, right heart catheterisation is required to diagnose PAH and monitor response to treatment. Right heart catheterisation is an invasive test, and alternatives such as echocardiography have not yielded sufficient accuracy both for early diagnosis and disease monitoring. Currently, PAH is often diagnosed at an advanced stage of the disease. There is often a delay in diagnosis of several years between the first symptoms and the identification of the disease due to the non-specific nature of symptoms. Hence, there is the need to improve the time between the first signs and definitive diagnosis of the disease. Early diagnosis of PAH remains a challenge due to the low sensitivity and specificity of biomarkers available currently.