Heartburn (GERD)

What Causes GERD?

GERD occurs when a muscle at the lower end of the esophagus does not work properly. The muscle is called the lower esophageal sphincter (LES). Sphincters are ring-like bands of muscle that contract, or squeeze together, to close off body passageways. The body has many sphincters. Perhaps the most familiar is the anal sphincter, which seals off the rectum between bowel movements.

  • The LES acts like a one-way valve that closes off the esophagus. It allows food to travel freely downward into the stomach. But it also seals off the stomach, preventing partially digested food from refluxing, or passing back up, through the esophagus.
  • Normally, the LES closes immediately after a person swallows food, keeping irritating stomach acid and digestive enzymes out of the esophagus.
  • In individuals with GERD, the LES may not close in a normal way or relaxes inappropriately between swallows. Stomach juices and partially digested food may flow back up and burn the lower esophagus. The result is heartburn and other symptoms ofGERD.

GERD and Hiatal Hernia

A hiatal hernia occurs when part of the upper stomach bulges, or herniates, into the chest cavity. It bulges through a natural opening in the diaphragm where the esophagus enters the abdominal cavity. A hiatal hernia is named for the opening, which is called the esophageal hiatus. Some people are born with a hiatal hernia. Others develop one later in life.

A hiatal hernia can contribute to GERD in two ways:

  • The diaphragm muscles normally wrap around the lower esophageal sphincter (LES). These muscles contract with the LES, adding their force to help close off the esophagus and prevent reflux. When a hiatal hernia occurs, the LES slides up into the chest cavity. But since the diaphragm remains in the same place, it can no longer add its muscle power to the LES. As a result, the LES does not contract completely.
  • The esophagus normally connects to the stomach at a sharp angle. Tissue from the esophagus and stomach at this point form a bend that acts like a second stomach valve. When the stomach is full, the bend can help seal off the stomach and prevent reflux. When a hiatal hernia pulls the stomach into the chest, the bend becomes less sharp and is less effective as a valve.

Nice To Know:

Is there a link between GERD and asthma?

Although the two diseases seem very different, doctors think that a connection may exist. Asthma is a condition in which the small airways in the lungs are inflamed. Many people with asthma also have an abnormal lower esophageal sphincter. In addition, there have been medical reports of asthma patients being cured after surgery for hiatal hernia. Treatment of GERD with drugs or lifestyle changes may also reduce asthma symptoms.

Doctors think that GERD can cause asthma symptoms in two ways:

  1. By irritating the lungs. People with GERD may inhale droplets of acid material into their lungs without being aware of it. The acid material irritates the delicate lining of the lungs, causing small airways to go into spasm. The irritation may trigger an asthma attack or chronic cough.
  2. By irritating nerve endings. Acid may dissolve the lining of the esophagus, exposing parts of a major nerve that also affects the lungs. Irritation of the nerve sends a signal to the lungs, causing small airways to go into spasm.

Doctors often suspect that GERD is causing asthma when:

  • Asthma begins in an adult.
  • Asthma symptoms get worse at night, after meals, or after lying down.
  • Standard asthma treatments do not relieve symptoms.

 

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