Why are they breathless: Could it be pulmonary arterial hypertension?

Pulmonary arterial hypertension (PAH) comprises a group of rare diseases presenting as unexplained dyspnoea. • Diagnosis of PAH is often delayed by more than 18 months. • Consider the possibility of PAH in patients presenting with breathlessness. • Detailed evaluation, including a right heart catheterisation, is needed for patients with PAH. • Pulmonary hypertension is a common finding on transthoracic echocardiography, but it is rarely PAH. • New treatments for PAH are available that can improve quality of life, exercise capacity and survival.