Pulmonary hypertension (PH) is a hemodynamic and pathophysiological condition, in which there is a mean pressure of
≥ 25 mmHg in arteria pulmonalis during the right-side heart catheterization performed at rest. It can be present in numerous
pathological instances, most frequently it is presented as a complication of cardiovascular and pulmonary diseases
and almost always signifies a negative prognostic factor. Some forms of PH belong to less known or rare diseases
frequently associated with malignant behaviour. The authors present innovations of definition and classification of
PH brought on by the latest guidelines of the European Society of Cardiology in 2015.