WHY DO HERNIAS OCCUR ? Any condition that increases the pressure of the abdominal cavity over a prolonged period of time may become a cause for hernia eg. Obesity, chronic cough, heavy lifting, chronic constipation leading to straining during bowel movement. Family history of hernia makes one more likely to get it. Some hernias may be present at birth Idiopathic, which means the cause is not known. Best piles hernia surgeon in Pune.