Correct answer:

Hernias occur at sites of weakness in the abdominal wall. The weakness may be congenital, e.g. persistence of the processus vaginalis of testicular descent giving rise to a congenital inguinal hernia, or failure of complete closure of the umbilical scar. It may occur at the site of penetration of sutures through the abdominal wall, e.g. the femoral canal, or the layers of the abdominal wall may be weakened following a surgical incision (incisional hernia), either by poor healing as a result of infection, haematoma formation or poor technique or by damage to nerves that results in paralysis of the abdominal muscles. Hernias should also be thought of as portents of other diseases or conditions, as they are often associated with pathological increases in intra-abdominal pressure by conditions such as:
(1) chronic cough, secondary to chronic bronchitis;
(2) constipation, perhaps due to colonic carcinoma;
(3) urinary obstruction, due to prostatic disease;
(4) pregnancy;
(5) abdominal distension with ascites;
(6) weak abdominal muscles, e.g. in gross obesity or muscle wasting in cachexia.