• The pathogenesis of this disease process is multifactorial, including abnormalities in the lower esophageal sphincter function, esophageal motility, and gastric motility or emptying.

• Food passes through the esophagus into the stomach when the lower esophageal sphincter relaxes before the esophagus contracts. In resting conditions, the lower esophageal sphincter is typically a high-pressure zone, in fact, 15-30 mmHg above intragastric pressures. Some people can have a constantly weak lower esophageal sphincter pressure, which causes acid reflux when the pressure of the stomach exceeds the pressure of the LES. Factors that create this decrease in pressure (<6 mmHg) include endogenous hormones, such as progesterone in pregnancy, medications like calcium channel blockers, foods high in fat, and habits such as consumption of nicotine and caffeine.

• Another abnormality in the function of the lower esophageal sphincter that contributes to the progression of GERD is transient lower esophageal sphincter relaxations (TLESRs), which allow gas venting from the stomach. These relaxations are unrelated to swallowing or peristalsis. Studies indicate that TLESRs are actually visceral reflexes that are induced by gastric distension or stimulation of receptors of gastric tension and stretch. Similar to abnormalities in the lower esophageal sphincter, TLESRs are influenced by fatty foods, alcohol, and smoking.

• Impaired esophageal clearance is a critical factor leading to GERD. This particular process (esophageal acid clearance) is the most significant protective mechanism against GERD, so when it is disrupted, GERD can develop. This process includes peristalsis and the consumption of salivary bicarbonate. The degree and duration of acid exposure to the esophagus determines the degree of esophageal mucosal injury. Impaired esophageal clearance can be caused by an increase in reflux volume or occasionally by an underlying condition. When this process is impaired, peristalsis is then characterized by low-amplitude contractions, therefore, incomplete esophageal emptying. Also, impaired esophageal clearance can cause re-reflux, which is when the contents get trapped in a hiatal hernia leading to those contents then getting returned to the esophagus after the relaxation of the lower esophageal sphincter. Furthermore, clearance of stomach acid is prolonged when there is a reduced salivary rate because the acid is neutralized at a slower pace. This can be caused by anticholinergic drugs and smoking.

• A delay in gastric emptying results in the retention of highly acidic contents in the stomach, which can progress to GERD. Delayed gastric emptying increases the amount of reflux, causing gastric distention. Studies have shown that gastric distension is linked to transient lower esophageal sphincter relaxations (TLESRs). The increase in intragastric pressure caused by a buildup of reflux contents overpowers the lower esophageal sphincter.

• Hiatal hernias can be described as a condition when part of the stomach pushes into the chest cavity, causing the diaphragm to be separated from the lower esophageal sphincter. Because of this disruption, there is an increase in acid exposure to the esophagus. This is directly related to the chronicity of GERD. Hiatal hernias also can act as a reservoir for acidic content, which increases susceptibility to acid reflux. In this case, the acid gets trapped in the hernia, and then gets refluxed into the esophagus when the lower esophageal sphincter relaxes (during swallowing).

• Esophageal mucosa resistance is directly related to the development of GERD. The esophagus has several components that form a protective barrier against harmful substances. These mechanisms include a weak pre-epithelial defense and a strong epithelial defense supported by a blood supply. The pre-epithelial layer consists of a small water layer that has a limited capacity when it comes to buffering. However, the buffering capacity is sufficient to maintain the surface pH values without activation of pepsin. When this mechanism fails, it is solely up to the epithelium itself to provide defense. This defense system is made of the cell membranes and intercellular junction complex, cellular and intercellular buffers, and cell membrane ion transporters. All of these defense mechanisms can be defeated by highly acidic reflux, or ingestion of smoke-derived chemicals, alcohol, or substances high in osmolality. When the esophageal defense mechanisms are overwhelmed, mucosal injury occurs. This then leads to acid and acid-pepsin attacking the intercellular junctions. Because of the damage to these junctions, there is an increase in paracellular permeability, and intracellular acidification occurs. This is present in the esophageal epithelium of those with GERD.

• A physical examination and history of signs and symptoms relating to a patient’s experience with acid reflux may suffice for a doctor to diagnose GERD. However, in order to confirm the diagnosis or check for complications, specific tests are recommended.

• Upper gastrointestinal GI endoscopy and biopsy: An endoscope is fed through the mouth and throat to observe the lining of the esophagus, stomach, and duodenum, which comprise the upper GI tract. Then, a small piece of tissue if cut out to examine for the presence of GERD. An endoscopy can detect esophagitis, hyperemia, edema, erosion, and structures. The biopsy can be tested for Barrett’s esophagus, which is when the lining of the esophagus begins to resemble that of the small intestine.

• Upper GI series: X-rays of the upper GI tract (esophagus, stomach, and duodenum) are taken to observe for GERD. Barium is a liquid that the patient drinks prior to the procedure in order to get better visualization of the x-rays as it moves through the upper GI tract. This test can help to diagnose the narrowing of the esophagus, which can cause complications with swallowing.

• Esophageal pH and impedance monitoring and Bravo wireless esophageal pH monitoring: A thin tube is inserted either through the nose or mouth into the stomach. Then, the patient is sent home with the monitor which is used to record their pH as they follow their normal, everyday patterns, especially in regard to eating and sleeping. The esophageal pH and impedance monitors are worn for 24 hours, while the Bravo monitoring system is worn for 48 hours. These monitors identify when, and for how long, stomach acid regurgitates in the esophagus.

• Esophageal manometry: A small, flexible tube with sensors is inserted into the nose. The sensors are used to measure the strength of the lower esophageal sphincter and esophageal muscles as the patient swallows. The functionality of the sphincter, muscles, and spasms to move food from the esophagus to the stomach can display GERD if it is not consistent with normal functioning.

• Heart burn (pyrosis): Frequent, persistent heart burn that interferes with a person’s everyday routine is common with GERD because stomach acid gets backed up in the throat causing that sensation.

• Acid regurgitation: A sensation of acid backing up in the throat is present. This can cause a sour or bitter taste in the mouth.

• Dysphagia: When stomach acid back up, it irritates the lining of the esophagus. Persistent heartburn leads to dysphagia because it causes the esophagus to scar and narrow and causes esophageal spasms.

• Chronic cough: A hacking, dry cough at night that persists for 8 weeks or longer is commonly seen in those with GERD. This cough is a protective mechanism against acid reflux.

• Asthma attacks: The repeated backup of stomach acid in the esophagus damages the lining of the throat and the airways to the lungs. This can lead to difficulty breathing, therefore, triggering asthma attacks.

• Laryngitis: The backflow of stomach acid into the throat causes the vocal folds to get irritated and swell, causing this voice disorder.

• Hoarseness: The most common cause of hoarseness is acute laryngitis because it affects the sound-producing larynx. This condition causes the voice to sound raspy, breathy, and strained.

• Upper abdominal pain within 1 hour of eating: Since GERD is caused by the loosening of the lower esophageal sphincter, which is crucial when passing food from the esophagus to the stomach, upper abdominal pain is consistent with the disease. Because of this disruption, food is not being digested correctly, which irritates the upper abdomen and throat. This upper abdominal pain is usually present alongside heart burn.

• Lifestyle changes and over-the-counter medications are recommended first when treating GERD. However, if symptoms are not relieved after a few weeks, prescribed medications or surgery are considered as options.

1. Weight reduction: Excess weight causes increased abdominal pressure, which increases the occurrence of acid reflux, so losing that extra weight has a huge effect on reducing that backflow of acid. 
   

2. Smoking cessation: Nicotine relaxes the lower esophageal sphincter, which causes stomach acid and juices to back up in the esophagus leading to heartburn. Eliminating nicotine intake prevents this relaxation.
   

3. Elevation of the head of the head 6 inches: Elevating the head of the bed to this position sets the esophagus over the stomach. This makes it harder for stomach acid to escape, therefore, preventing the backflow of stomach acid into the esophagus. 
   

4. Avoiding tight clothing: Tight clothing puts pressure on the stomach, which forces stomach acid to move towards the esophagus. Avoiding this type of clothing helps to prevent acid reflux, which can cause heartburn. 
   

1. Antacids that neutralize stomach acid: Mylanta, Rolaids, and Tums can provide quick relief but should be used with caution because they can cause diarrhea and kidney problems with overuse.
   

2. Medications to reduce acid production: These H-2-receptor blockers include cimetidine (Tagamet HB), famotidine (Pepcid AC), and nizatidine (Axid AR). These medications provide longer relief than antacids and reduce stomach acid production as long as 12 hours.
   

3. Medications that block acid production and heal the esophagus: These proton pump inhibitors include lansoprazole (Prevacid 24 HR) and omeprazole (Prilosec OTC, Zegerid OTC). These medications are stronger than H-2-receptor blockers and allow time for the esophagus to heal from damage caused by acid reflux.
   

1. Prescription-strength H-2-receptor blockers: Prescription-strength famotidine (Pepcid) and nizatidine comprise these medications. Long-term use of these medications can cause an increase in the risk for both vitamin B-12 deficiency and bone fractures. 
   

2. Prescription-strength proton pump inhibitors: These medications include esomeprazole (Nexium), lansoprazole (Prevacid), omeprazole (Prilosec, Zegerid), pantoprazole (Protonix), rabeprazole (Aciphex), and dexlansoprazole (Dexilant). Side effects of these medications include headache, nausea, diarrhea, vitamin B-12 deficiency, and hip fracture with chronic use. 
   

3. Medication to strengthen the lower esophageal sphincter: Baclofen is a medication that decreases lower esophageal sphincter relaxations, but it can cause fatigue and nausea.
   

1. Fundoplication: The top of the stomach is wrapped around the lower esophageal sphincter to tighten it, therefore, preventing reflux. The wrapping of the stomach can be partial or complete.
   

2. LINX device: The junction of the stomach and esophagus is wrapped with tiny magnetic beads. The attraction between the beads allows the junction to remain closed when acid reflux occurs, however, food is able to pass through the junction.
   

3. Transoral incisionless fundoplication (TIF): An endoscope is used to tighten the lower esophageal by partially wrapping it around the lower esophagus using polypropylene fasteners. 
   

• GERD is the reflux of acid and pepsin or bile salts from the stomach into the esophagus, causing esophagitis.

• Physiologic reflux is GERD that does not cause symptoms.