Widening of the intermuscular veins may be caused by physiological or pathological factors such as thrombosis and elevated venous pressure. 1. Physiological factors: standing for too long time may cause poor local blood return, which may temporarily cause widening and expansion of the intermuscular veins in severe cases, and the symptoms can be gradually relieved and disappear after timely rest. 2.Pathologic factors (1) Thrombus: blood in high coagulation state can cause thrombus, thus causing local venous return obstruction, blood stasis and even vascular deformity, which can be manifested as widening and dilatation of intermuscular veins. (2) Elevated venous pressure: When the venous blood pressure continues to rise, the impact of venous blood on the tendons can also cause widening and dilatation of the intermuscular veins. If symptoms of widening of the interosseous veins occur, it is recommended to go to the hospital in time to find out the cause of widening after eliminating the physiological factors, and actively treat the cause of widening in order to avoid delaying the condition.