Inguinal hernia

Part of an internal organ that protrudes through an abnormal opening in the wall of the cavity that surrounds it
Most common type of hernia (see Common sites of hernia)
Possibly direct or indirect, reducible (able to return contents into abdominal cavity spontaneously or with manipulation), incarcerated (no longer reducible without compromise to vascular supply), or strangulated (incarcerated with compromise to the vascular supply)

In an inguinal hernia, the large or small intestine, omentum, or bladder protrudes into the inguinal canal.
In an indirect hernia, abdominal viscera leave the abdomen through the inguinal ring and follow the spermatic cord (in males) or round ligament (in females); they emerge at the external ring and extend down into the inguinal canal, commonly into the scrotum or labia.
In a direct inguinal hernia, instead of entering the canal through the internal ring, the hernia passes through the posterior inguinal wall, protrudes directly through the transverse fascia of the canal (in an area known as Hesselbach’s triangle ), and emerges at the external ring.

Direct—weakness in fascial floor of inguinal canal
Either—weak abdominal muscles (caused by congenital malformation, trauma, or aging) or increased intra-abdominal pressure (caused by heavy lifting, pregnancy, obesity, or straining)
Indirect—weakness in fascial margin of internal inguinal ring