A lateral abdominal wall mass with fixed pressure pain is the main symptom of a hallux valgus hernia. Congenital semilunar hernias are relatively rare and most are acquired. The semilunar tendon membrane is one of the congenital weak areas of the anterior abdominal wall, and the semilunar tendon membrane structure is generally considered to be most closely associated with the development of semilunar hernias. Other predisposing factors are similar to other extra-abdominal hernias (including increased intra-abdominal pressure and disorders of collagen metabolism). In humans, intra-abdominal pressure is greatest in the lower abdomen when walking upright, while the posterior sheath terminates in the mid-lower abdominal position, and thus a hemilineal hernia most often occurs in this region. Advanced age and weight loss are generally considered important causative factors for semilunar hernias. Paralysis of the abdominal wall muscles is also a possible pathogenetic factor. So how should we examine this disease? On physical examination, a reducible mass is found along the semilunar tendon membrane, which appears when the patient is upright and disappears spontaneously when lying down. The patient should be asked to alternate between tensing and relaxing the abdominal wall during the examination. When the patient’s abdominal wall is tensed, all patients with a semilunar ventral hernia have a tender spot in the hernia ring within their semilunar tendon membrane. Ultrasound and CT are effective adjuncts.