Lymphatic vessels, part of the secondary circulatory system in the human body, play multifaceted roles in maintaining homeostasis among tissues and organs. They regulate lymph absorption and transport, immune surveillance, and responses. The development of lymphatic vessels involves sophisticated regulatory signaling pathways that govern the assembly of heterogeneous cell populations into specialized networks. Lymphangiogenesis, the formation and expansion of lymphatic networks from pre-existing vessels or embryonic veins, is a key developmental mechanism. Abnormal lymphangiogenesis is associated with various diseases, such as lymphedema, obesity, and cancer. Mechanistic studies have identified lymphangiogenic factors and cascades that can be targeted to modulate abnormal lymphangiogenesis and improve treatment efficacy. This review provides a comprehensive overview of lymphatic vessel development, physiological functions, and therapeutic targets, highlighting the critical role of abnormal lymphangiogenesis in multiple diseases and the potential of current treatments.Lymphatic vessels, part of the secondary circulatory system in the human body, play multifaceted roles in maintaining homeostasis among tissues and organs. They regulate lymph absorption and transport, immune surveillance, and responses. The development of lymphatic vessels involves sophisticated regulatory signaling pathways that govern the assembly of heterogeneous cell populations into specialized networks. Lymphangiogenesis, the formation and expansion of lymphatic networks from pre-existing vessels or embryonic veins, is a key developmental mechanism. Abnormal lymphangiogenesis is associated with various diseases, such as lymphedema, obesity, and cancer. Mechanistic studies have identified lymphangiogenic factors and cascades that can be targeted to modulate abnormal lymphangiogenesis and improve treatment efficacy. This review provides a comprehensive overview of lymphatic vessel development, physiological functions, and therapeutic targets, highlighting the critical role of abnormal lymphangiogenesis in multiple diseases and the potential of current treatments.