In recent years, isolated systolic hypertension (ISH) has been increasingly reported in young adults, particularly lean men. This phenomenon, traditionally associated with advanced age and arterial stiffness, is now more frequently diagnosed in individuals under 50 years of age, raising numerous controversies regarding both its clinical interpretation and therapeutic management. In contrast to the older population, where ISH constitutes a significant cardiovascular risk factor, young individuals often present with so-called “pseudo-ISH” – a form of systolic hypertension resulting from physiological pulse-wave amplification, without accompanying pathological changes in the cardiovascular system. The aim of this review is to summarize the current state of knowledge on ISH in young adults, with particular emphasis on its pathophysiology, diagnostic tools (ambulatory blood pressure monitoring, home blood pressure monitoring, central blood pressure measurement, pulse wave velocity), prognostic significance, and therapeutic approach. Current controversies related to differentiating systolic–diastolic hypertension from its physiological variants are discussed, and the need for further research to unequivocally determine the risk and management strategies in this patient population is highlighted.