Medically, a hernia is a tear in body tissues, especially muscle, that allows displacement of body organs. There are three particularly important types of hernias in humans:
inguinal hernia: almost exclusively found in males, these are a tear in the musculature and tissues of the lower abdomen, allowing an intestinal loop to protrude through the front abdominal wall, and are of two types:
indirect inguinal hernia, in which the rift is through the testicular canal,
direct inguinal hernia, in which the rift is a direct tear through the abdominal wall
umbilical hernia: a tear in the tissues around the umbilicus, or navel, allowing organs to protrude through the anterior abdominal wall