- Structural weakness
- Congenital: patent processus vaginalis, incomplete fusion of fascia
- Acquired: fascial attenuation or disruption (e.g. incisional hernias)
- Increased intra-abdominal pressure
- Chronic cough, constipation, obesity, ascites, pregnancy, heavy lifting
- Pressure exceeds tensile strength of weakened abdominal wall
- Tissue failure
- Disruption in collagen metabolism (↑ type III : type I collagen ratio)
- Seen in smokers, diabetics, elderly, or patients on corticosteroids
- Leads to poor wound healing and fascial integrity