Causes, Risk Factors and Prevention of Acid Reflux Disease
A brief tour of the anatomy of the stomach and esophagus will help you understand what causes acid reflux disease. Think of the esophagus as an upright sausage that connects to the stomach at the lower end and throat at the upper end. It is narrowed at both the bottom and top by two contracting muscles known as sphincters. The lower esophageal sphincter (LES) is at the bottom in an area called the gastroesophageal junction. The upper esophageal sphincter (UES) is at the top, adjacent to the throat. When one swallows, the esophageal sphincters must temporarily relax and open, allowing food to travel to the stomach.
If you are experiencing serious medical symptoms, seek emergency treatment immediately.
As soon as food passes through the sphincters, they must tighten back up. Both gravity and peristalsis (a coordinated series of muscle contractions in the esophagus) help food move in the proper direction, from high to low.
If the LES doesn’t tighten closed after food passes from the esophagus into the stomach, acid from the stomach can flow back up into the esophagus, resulting in gastroesophageal reflux disease (GERD). Pepsin, an enzyme produced by the stomach, accompanies the refluxed acid. Bile acids from the first part of the intestines — the duodenum — are also occasionally refluxed with the stomach acid.
Similarly, if the UES doesn’t tighten closed after food passes from the throat to the esophagus, the caustic gastric contents can travel all the way up into the throat, resulting in laryngopharyngeal reflux disease (LPRD).
Acid reflux occurs when the normal mechanisms keeping acid in the stomach are disrupted. This can be caused by changes in LES pressure, peristalsis and intragastric pressure, or pressure within the stomach. Reflux occurs when the pressure is high enough to overcome the pressure at the gastroesophageal junction, forcing the LES to open. The most common example of this is abdominal obesity. Intragastric pressure can also increase when the stomach doesn’t empty normally. This is known as delayed gastric emptying. It is common in pregnancy, but may also occur with certain medications (such as opioid painkillers) and in people with certain diseases (such as diabetes).
- Acid reflux occurs when the normal mechanisms keeping acid in the stomach are disrupted.
- This can be caused by changes in LES pressure, peristalsis and intragastric pressure, or pressure within the stomach.
Acid Reflux and Regurgitation
Situations that relax the LES itself can cause acid reflux. Tobacco is one of the most potent and common relaxers of the LES. Various medications, such as antidepressants and certain asthma medications, may also cause relaxation of the sphincter and thereby lead to acid reflux. Tobacco smoking also relaxes the UES, which is one reason why it can also produce symptoms of LPRD.
Anatomic abnormalities around the gastroesophageal junction can also interfere with normal functioning of the LES. A prime example of this is a hiatus hernia, which is a condition in which part of the stomach is located in the chest instead of the abdomen. This causes the LES to close poorly, promoting acid reflux.
- Situations that relax the LES itself can cause acid reflux.
- Various medications, such as antidepressants and certain asthma medications, may also cause relaxation of the sphincter and thereby lead to acid reflux.
Impaired Esophageal Peristalsis
Even if acid flows from the stomach to the esophagus, it may cause no problems if the amount is small and if peristalsis in the esophagus is normal. When peristalsis is impaired — a condition called esophageal dysmotility — acid that is refluxed back into the esophagus will not be promptly pushed back into the stomach. It therefore stays in the esophagus, causing damage.
What’s Special About Laryngopharyngeal Reflux Disease?
What Causes Indigestion & Hiccups?
Pepsin plays an important role in causing LPRD. When pepsin is refluxed up from the stomach into areas above the esophagus, such as:
- the vocal cords
- middle ear
- it can remain in these areas for quite awhile
Pepsin becomes activated in acidic environments. So if a person consumes food or liquid that is very acidic, pepsin in these areas will become activated and cause inflammation. Therefore, with LPRD, it’s not only what comes up from the stomach that may be irritating the body, but also the activated pepsin that is residing in these areas.
- Pepsin plays an important role in causing LPRD.
- Therefore, with LPRD, it’s not only what comes up from the stomach that may be irritating the body, but also the activated pepsin that is residing in these areas.
Acid Reflux and Regurgitation
What Causes Indigestion & Hiccups?
Does Weightlifting Cause GERD Symptoms?
Why Does Drinking Water Create Acidity?
The Best Foods to Eat for GERD Patients
Acid Reflux and Chest Pressure
Esophageal Hernia Symptoms
How to Get Rid of Acid Reflux Burps
Pain Symptoms of a Hiatus Hernia
Foods to Stay Away From With a Bad Esophagus
- National Institute of Diabetes and Digestive and Kidney Diseases. Symptoms & causes of GER & GERD. November 2014.
- National Institute of Diabetes and Digestive and Kidney Diseases. Diagnosis of GER & GERD. November 2014.
- Harvard Women's Health Watch. 9 ways to relieve acid reflux without medication. Harvard Health Publishing. September 10, 2019.
- US Food and Drug Administration. Over-the-counter (OTC) heartburn treatment. March 3, 2018.
- Gastroenterology: A Challenge to Esophagogastric Junction Integrity.
- Best Practice and Research - Clinical Gastroenterology: The Role of Delayed Gastric Emptying and Impaired Oesophageal Body Motility
- Journal of Clinical Gastroenterology: Pathophysiology of Gastroesophageal Reflux Disease.
- Journal of Laboratory and Clinical Medicine: The Effect of Cigarette Smoking on Salivation and Esophageal Acid Clearance.
- Gut: Effect of Chronic and Acute Cigarette Smoking on the Pharyngo-Upper Oesophageal Sphincter Contractile Reflex and Reflexive Pharyngeal Swallow.
- The New England Journal of Medicine: The Esophagogastric Junction.
- Neurogastroenterology and Motility: The Lower Esophageal Sphincter.
- Alimentary Pharmacology and Therapeutics: The Clinical Relevance of Transient Lower Oesophageal Sphincter Relaxations in Gastro-Oesophageal Reflux Disease.
- Laryngoscope: The Otolaryngologic Manifestations of Gastroesophageal Reflux Disease (GERD)
- The American Journal of Medical Sciences: Role of Saliva in Esophageal Defense - Implications in Patients with Nonerosive Reflux Disease.
Jonathan Aviv, M.D., is the clinical director of the Voice and Swallowing Center, ENT and Allergy Associates, and clinical professor of Otolaryngology at the Icahn School of Medicine at Mount Sinai Hospital. He is a former professor of Otolaryngology-Head and Neck Surgery at the College of Physicians and Surgeons, Columbia University. He invented a medical device (FEESST) and authored 63 peer-reviewed articles as well as the book “Killing Me Softly From Inside.”