hiatal hernia : What Are The Symptoms And How Does It Cause GERD?

The symptoms of a hiatal hernia

The vast majority of hiatal hernias are 'sliding' hiatal hernias in which the junction of the esophagus and stomach, referred to as the gastroesophageal junction, and part of the stomach protrudes into the chest. The larger the hernia, the more likely it is to cause symptoms. When hiatal hernias produce symptoms, they are almost always those of gastroesophageal reflux disease (GERD) or its complications.

This happens because the formation of the hernia often interferes with the barrier (lower esophageal sphincter) which prevents acid from refluxing from the stomach into the esophagus. Patients with GERD are more likely to have a hiatal hernia than individuals not afflicted by GERD. Although hiatal hernias contribute to GERD, it is not clear if hiatal hernias alone can result in GERD. Since GERD occurs in the absence of a hiatal hernia, factors other than the existence of a hernia can cause GERD.

How a hiatal hernia causes GERD

GERD is when acid flows backwards (refluxes) up into the esophagus. Normally, there are several devices to prevent this from happening.

One device involves a band of esophageal muscle, where the esophagus joins the stomach. This is called the lower esophageal sphincter; it remains contracted most of the time to prevent acid from refluxing or regurgitating.

The sphincter only relaxes when food is swallowed so that the food can pass from the esophagus and into the stomach. The sphincter is normally attached firmly to the diaphragm in the hiatus, and the muscle of the diaphragm wraps around the sphincter. The muscle that wraps around the diaphragm increases the pressure of the contracted sphincter to further prevent reflux of acid.

Another device that prevents reflux is the valve-like tissue at the junction of the esophagus and stomach just below the sphincter. The esophagus normally enters the stomach logically so that there is a sharp angle between the esophagus and stomach. The thin piece of tissue in this angle, composed of esophageal and stomach wall, forms a valve that can close off the opening to the esophagus when pressure increases in the stomach; during a belch, for instance.

When a hiatal hernia is present, two changes happen:

The sphincter slides up into the chest while the diaphragm remains stationery. As a result, the pressure normally generated by the diaphragm overlying the sphincter and the pressure generated by the sphincter no longer overlap. As a result, the total pressure at the gastroesophageal junction decreases. When the gastroesophageal junction and stomach are pulled up into the chest with each swallow, the sharp angle where the esophagus joins the stomach becomes less sharp and the valve like effect is lost.

Both changes promote reflux of acid, or GERD.

Hope for Hiatal Hernia!

Understanding the processes behind a hiatal hernia and GERD is the first step to treating it.

By Nick Willis