Key pointsPAH is defined by RHC showing a pre-capillary PH.Clinical suspicion of PH should arise in the case of symptoms such as dyspnoea without overt signs of specific heart or lung disease.RHC is required to confirm the diagnosis of PAH, to assess the severity of the haemodynamic impairment and to test the vasoreactivity of the pulmonary circulation.Variables that have been shown to predict prognosis in IPAH include baseline NYHA functional classification, history of right heart failure, baseline 6-minute walk distance, and baseline haemodynamics.FPAH segregates as an autosomal dominant trait, but with markedly reduced penetrance. Germline BMPR2 mutations have been detected in at least 60% of the families studied to date, as well as in cases of so-called IPAH.Basic PAH therapy includes oxygen, diuretics and warfarin.Chronic treatment with oral CCBs should be considered for PAH patients who respond to acute vasodilator challenge.Cohort analysis of IPAH patients receiving continuous intravenous epoprostenol, as compared to historical control groups, clearly demonstrated clinical benefits in NYHA functional class III and IV patients.Two double-blind, randomised, placebocontrolled trials have supported the efficacy of oral bosentan in patients with PAH class III.One double-blind, randomised placebocontrolled trial has supported the efficacy of oral sildenafil in patients with symptomatic PAH.Lung transplantation is the ultimate alternative for severe PAH cases who cannot be managed medically.Educational aimsTo improve awareness of PAH.To describe the novel classification of PH.To provide information regarding the therapeutic approach of PAH.SummaryPulmonary arterial hypertension (PAH) is a rare condition characterised by elevated pulmonary arterial resistance, leading to right heart failure. PAH can be sporadic (idiopathic PAH), familial or related to other conditions. Echocardiography is the investigation of choice for non-invasive screening. Measurement of haemodynamic parameters during right heart catheterisation (RHC) is mandatory to establish the diagnosis. Recent advances in the management of PAH include prostaglandins, endothelin receptor antagonists and PDE5 inhibitors. Lung transplantation is the last option for patients who deteriorate despite medical treatment. This review aims to update the reader on all these aspects of PAH.