Some inguinal hernias have no apparent cause. But many occur as a result of increased pressure within the abdomen, a pre-existing weak spot in the abdominal wall or a combination of the two. In men, the weak spot usually occurs along the inguinal canal. This is the area where the spermatic cord, which contains the vas deferens, the tube that carries sperm, enters the scrotum. In women, the inguinal canal carries a ligament that helps hold the uterus in place, and hernias sometimes occur where connective tissue from the uterus attaches to tissue surrounding the pubic bone.
More common in men
Men are more likely to have an inherent weakness along the inguinal canal than women are because of the way males develop in the womb. In the male fetus, the testicles form within the abdomen and then move down the inguinal canal into the scrotum. Shortly after birth, the inguinal canal closes almost completely, leaving just enough room for the spermatic cord to pass through, but not large enough to allow the testicles to move back into the abdomen. Sometimes, however, the canal doesn’t close properly, leaving a weakened area. There’s less chance that the inguinal canal won’t close after birth in female babies. In fact, women are more likely to develop hernias in the femoral canal, an opening near the inguinal canal where the femoral artery, vein and nerve pass through.
Weaknesses can also occur in the abdominal wall later in life, especially after an injury or certain operations in the abdominal cavity. Whether or not you have a pre-existing weakness, extra pressure in your abdomen can cause a hernia. This pressure may result from straining during bowel movements or urination, from heavy lifting, from fluid in the abdomen (ascites), and from pregnancy or excess weight. Even chronic coughing or sneezing can cause abdominal muscles to tear.