Vascular anomalies are a heterogenous group of diseases that include vascular tumours and vascular malformations. Over the past two decades, significant progress has been made in elucidating the genetic basis of these anomalies, leading to improved classification, management and genetic counselling. Major signalling pathways, such as RAS/MAPK/ERK, PI3K/AKT/mTOR, and G protein-coupled receptor pathways, have been identified as central to the pathogenesis of vascular anomalies. This article reviews the major types of vascular malformations, addresses the challenges associated with genetic testing and counselling, and explores the emerging potential for precision medicine in the treatment of these diseases.