Dilatation of the internal jugular vein refers to cystic or spindle-shaped dilatation of the jugular venous system, which may be caused by congenital factors such as poorly developed vein walls, as well as acquired causes such as venous thrombosis and right heart failure. 1. Congenital factors: This condition is most common in people with congenital dysplasia of the valves of the internal jugular vein, which is prone to stenosis, occlusion, and other obstacles to venous blood return, resulting in jugular vein dilatation. 2. Acquired factors: venous thrombosis causes jugular vein dilatation, mostly seen in people with long-term deep vein cannulation or traumatic injury, whose body is prone to the formation of venous thrombosis and blockage, resulting in jugular vein reflux obstruction. In people with right heart failure, the pumping function of the right ventricle is impaired, resulting in stagnation of the circulation and increased venous pressure, which leads to jugular vein dilatation. It is recommended that people with the disease should go to the hospital and take targeted treatment measures for different causes.