1.Why is varicocele more common on the left side than on the right side? Possible reasons: (1) The left internal spermatic vein has a long stroke and converges into the left renal vein at a right angle, which results in higher venous pressure. (2) The left renal vein is compressed between the superior mesenteric artery and the abdominal aorta, which affects the reflux of the left internal spermatic vein and even leads to reflux (“nutcracker” phenomenon). (3) The absence of internal spermatic vein valve is more common with the left side. 2.What are the causes of varicocele? Primary varicose veins are associated with the following factors: (1) absence or malfunction of the spermatic vein valves leading to reflux. (2) Weakness of the spermatic vein wall and surrounding connective tissue or underdevelopment of the levator muscle. (3) Upright posture affecting the reflux of spermatic veins. Secondary varicocele can be seen in obstruction of left renal vein or vena cava aneurysm, renal tumor, retroperitoneal tumor, pelvic tumor, giant hydronephrosis or renal cyst, spermatic cord vascular compression, etc. 3.How to diagnose varicocele? (1) Medical history: Patients with varicocele may have persistent or intermittent swelling, hidden pain and dull pain in the scrotum on the affected side, which is obvious when standing and walking and relieved after lying down and resting. Most patients are found to have painless earthworm-like masses in the scrotum during physical examination, or they are found when they visit the doctor for infertility. (2) Physical examination: The examination focuses on the scrotum and its contents, both in the standing and lying positions, and the Valsalva test is performed in the standing position to detect the presence of tortuous, dilated venous masses. The examination includes testicular size and texture, epididymis, vas deferens, spermatic cord and its blood vessels. A smaller and softer testicle is a sign of testicular insufficiency. (3) Color Doppler ultrasonography: color Doppler ultrasonography has important value for the diagnosis and typing of varicocele, and its diagnostic sensitivity and specificity are high. 4.How is varicocele graded? Varicocele can be clinically classified into 3 grades: Grade 1: palpable only after Valsaval action; Grade 2: palpable but not visible in standing position; Grade 3: visible and palpable by visual examination in standing position. In addition, if there are no abnormal clinical findings, but regurgitation of spermatic venous blood is detected by Doppler, it should be classified as subclinical type of varicocele.