In certain people the stomach acid contents regularly refluxes backwards into the esophagus, causing inflammation and damage of the lining of the tube. This is known as acid reflux.
This occurs because
- Muscle contraction normally keeps the lower end of the esophagus closed.
- As described earlier - normally the oesophageal muscles (where it enters the stomach) work in a mechanical action, wherein they squeeze themselves together to act as a shut-off valve, or tap, to keep stomach contents out.
- Hence reflux occurs when this valve like muscle is weak.
The reason why the muscle becomes weak is not fully understood.
Once the muscles become weak many factors like-
- Drinking too much alcohol
- Being overweight
- Wearing tight clothing
- Coffee, chocolate, fatty or spicy foods
- Certain medications (Commonly used drugs like Non-steroidal anti-inflammatory drugs [NSAIDs], nitrates, calcium channel blockers)
Can also increase the frequency of acid reflux.
Certain foods cause reflux, especially those that are
Sometimes reflux is caused by a 'Hiatus Hernia' (protrusion of a small part of the stomach above the diaphragm into the chest), which prevents the muscle at the base of the esophagus from working properly.
The acid is especially harmful and if persistent can cause permanent damage and lead to narrowing of the tube.
- Schwann, Theodor. Über das Wesen des Verdauungsprocesses. Arch Anat Physiol Wissensch Med. 1836; 90-138 [Reprinted in Selected Readings in the History of Physiology, 2nd ed. Translated by Fulton JF, Wilson LG. Springfield, IL: Charles C Thomas; 1966, pp. 190-2.
- Manipal Manual Of Surgery: K. Rajgopal Shenoy. MBBS, MS. (2000 EDITION)