Inguinal Hernia
A weakness in the abdominal wall at the inguinal canal lets peritoneal contents bulge through above and medial to the pubic tubercle, and the entire clinical picture (reducibility, cough impulse, and the danger of strangulation) follows from that defect being a tube the bowel can slide in and out of, or get trapped within.
First principles
A hernia is abdominal contents finding a weak point and pushing through it
The inguinal canal is a natural weak point in the anterior abdominal wall, present because the spermatic cord (or round ligament) must pass from the abdomen to the scrotum (or labia) during development. Raised intra-abdominal pressure (from straining, heavy lifting, chronic cough, or simply standing) pushes peritoneum, and often bowel or omentum, through this pre-existing passage. An indirect inguinal hernia follows the same path the testis took in development, through the deep inguinal ring, along the canal, and potentially into the scrotum; a direct inguinal hernia pushes straight through a weakened posterior wall of the canal (Hesselbach's triangle) without traversing the whole canal. Both emerge above and medial to the pubic tubercle, which is the anatomical fact that separates every inguinal hernia from a femoral hernia.
Educational content pending clinical review. Not medical advice.