Hypertrophic cardiomyopathies represent a heterogeneous group of pathophysiological mechanisms and etiologies (genetic or not), which lead to the development of left ventricular hypertrophy. Left ventricular hypertrophy, when not explained by a significant and prolonged increase in post-load (such as severe poorly controlled arterial hypertension or severe aortic stenosis) justifies etiological exploration. The etiology may range from physiological adaptation in the athlete to myocardial involvement, isolated or integrated as part of a global neuromuscular involvement; metabolic or mitochondrial disease to deposition disease. As cardiac signs are non-specific, the clinical examination should focus on looking for a syndromic entity. Considering this pathophysiological heterogeneity, in addition to the biological assays in search of a metabolic or infiltrative cause, the minimum check-up must include an electrocardiogram and a transthoracic echocardiography, which will most of the time be completed by magnetic resonance imaging, and even bone scintigraphy in the event of suspected amyloidosis. The question of genetic analysis and/or counselling should be systematically considered. The treatment is mainly symptomatic, aimed at controlling congestive signs and/or intraventricular obstruction, with the exception of amyloidosis and Fabry disease for which dedicated treatments have been developed. The rhythmic risk must be evaluated and can justify the implantation of an automatic defibrillator.