Pulmonary hypertension (PH) is classified into five groups. It is an important cause of dyspnoea. Echocardiography is the best non-invasive method for detecting PH and should be part of the evaluation of patients with dyspnoea. If signs of PH are detected on echocardiography, a number of other examinations should be undertaken to verify the diagnosis and classify PH correctly, as the treatment depends on the subtype of PH. The prognosis of PH is poor, but early detection and treatment can improve the course for some of the patients. Surgery can often cure chronic thromboembolic pulmonary hypertension.