Remodelling is one of the fundamental processes in the heart adaptation. It allows the heart to respond specifically to various stimuli and adapt to changed conditions. The basic remodelling processes involve hypertrophy and fibrosis. Remodelling is present at various levels and results in structural and subsequently functional changes in the myocardium. If the new state is compensated, it is referred to as physiological. Such remodelling includes so-called physiological hypertrophy induced by repeated sufficiently intense physical exertion. In pathological hypertrophy, the changes caused by remodelling are not sufficiently compensated. After adaptation to hemodynamic changes or under the influence of hormones promoting a pathological phenotype, the myocardium undergoes remodelling, which may lead to heart failure. Another form of myocardial remodelling is fibrosis. It typically occurs after a myocardial infarction in order to preserve the structural integrity of the heart. The process of fibrosis is also activated during hemodynamic overload, can be observed in toxic myocardial damage and in general in situations leading to the myocardial loss. These stimuli activate the fibroblasts present in the myocardium, which create new components of the intercellular mass forming a fibrotic structure. This review article aims to summarize the current knowledge of the mechanisms of cardiac remodelling. The article provides a comprehensive view of the current state of research and its potential contribution to clinical medicine.