Varicocele can be divided into primary and secondary, the more common one is primary varicocele, mostly seen on the left side, because the left spermatic vein converges into the left renal vein at a right angle, resulting in a higher blood return pressure in the left spermatic vein, and it is easy to have varicocele on the left side, which is determined by the anatomical structure, and at the same time the left spermatic vein is physiologically longer, and it is easy to be compressed by the sigmoid colon, which The left spermatic vein has a longer physiological course and is easily compressed by the sigmoid colon, resulting in venous valve insufficiency and thus varicose veins on the left side. If patients are found to have right spermatic varicose vein, they need to exclude the possibility of secondary causes, such as a huge retroperitoneal tumor compressing the right spermatic vein, or advanced kidney cancer with cancer thrombus blocking the right spermatic vein as well as the inferior vena cava, which will lead to the obstruction of blood return in the right spermatic vein and manifest as right spermatic varicose vein. These secondary varicoceles require specific tests to rule them out.