GERD & Hiatal Hernia

Nothing about the esophagus is built to hold acid. What protects it is a barrier at the esophagogastric junction made of several cooperating parts: the lower esophageal sphincter (LES), a 3–5 cm ring of smooth muscle with a resting tone of about 15–30 mm Hg that opens only for swallowed food; the crural diaphragm, which wraps the LES like an external sphincter and squeezes hardest during inspiration and any rise in abdominal pressure; a short segment of esophagus lying inside the abdomen, where positive pressure helps keep it closed; the acute angle of His between esophagus and fundus, which works with the gastric sling fibers as a flap valve; and the phrenoesophageal ligament, which anchors the whole assembly to the diaphragm.

The most common way the barrier opens — in healthy people and in GERD — is the transient LES relaxation (TLESR). Gastric distension with air or food fires a vagovagal reflex, the LES lets go for roughly 10–45 seconds, and gastric acid, peptic enzymes, and bile acids regurgitate upward. Everyone has TLESRs; in GERD they are more frequent, and increased intra-abdominal fat raises both the gastroesophageal pressure gradient and the TLESR count. The second failure is a low resting LES pressure or inappropriate relaxation: fat, chocolate, smoking, and alcohol each lower LES tone, as do nitrates, calcium channel blockers, anticholinergics, α-adrenergic agonists, theophylline, and morphine — the medication list behind the "did anything new get started?" question.

Behind those two sits a longer ACG 2022 list of contributors: a poorly functioning esophagogastric junction, LES and crural-diaphragm dysfunction, impaired esophageal clearance, altered mucosal integrity, decreased salivary production, delayed gastric emptying, and esophageal hypersensitivity. Raised intra-abdominal pressure — obesity from outside, pregnancy or large-volume ascites from inside — pushes gastric contents against a barrier that is already weak. Reflux (GER) is normal and usually symptomless; GERD is reflux that produces repeated bothersome symptoms — patient pages frame it as symptoms two or more times a week — or complications over time. About 20% of US adults have it.

A hiatal hernia is the abnormal protrusion of the stomach (or, rarely, other abdominal organs) through the diaphragm’s esophageal hiatus into the thorax — in patient language, "the upper part of your stomach bulges through an opening in your diaphragm." It is astonishingly common: roughly 55–60% of people over 50 have one, yet only about 10% develop symptoms, and the hernia by itself rarely hurts; discomfort comes from the upward flow of acid, air, or bile it permits. The anatomy explains the reflux. Displacing the stomach upward pulls the LES out of the crural diaphragm’s grip, so the "external sphincter" no longer squeezes the "internal" one, and the herniated pouch acts as a reservoir for gastric contents that reflux each time the LES relaxes with a swallow. A hiatal hernia therefore "compromises the integrity of the lower esophageal sphincter and is a leading cause of gastroesophageal reflux disease."

There are four types, and the split that matters is sliding versus paraesophageal. Type I — sliding: the gastroesophageal junction (GEJ) and the cardia slide up into the mediastinum together; this is the overwhelming majority, about 90–95%. Type II — paraesophageal: the fundus herniates alongside a GEJ that stays below the hiatus; the rarest form, under 5%. Type III — mixed: both the GEJ and a variable portion of stomach sit in the chest. Type IV: the stomach plus other organs — colon, spleen, small intestine — herniate upward. Types II–IV together are the paraesophageal hernias (PEH), and they carry the mechanical problems: dysphagia, chest pain, dyspnea, early satiety and postprandial fullness, and respiratory symptoms in 30–44% of surgical candidates.

Two hernia-specific complications live inside that pouch. Cameron lesions are linear erosions or ulcers on the gastric folds where the diaphragm repeatedly rubs and compresses the herniated stomach — friction plus localized ischemia plus acid — and they leak blood slowly enough to present not as bleeding but as iron-deficiency anemia (microcytic, hypochromic, low ferritin); they are found in 3–5% of hernias at endoscopy and 10–20% of hernias larger than 5 cm, and are often missed because they hide in the sac. The other is the emergency: a fundus lying beside a fixed GEJ can twist on itself — gastric volvulus, rotation of more than 180° — and a paraesophageal hernia is the most common cause of it. The chain is foregut obstruction → strangulation → necrosis → perforation → shock, and strangulated volvulus left untreated historically carried 30–50% mortality — with timely surgery, 30-day mortality is now about 6%.

Refluxed acid is normally cleared fast: peristalsis sweeps it back into the stomach and salivary bicarbonate neutralizes what remains. In GERD, dysregulated peristalsis clears acid poorly and saliva neutralizes less, so mucosal contact time lengthens — and weak LES pressure and "ineffective esophageal motility often accompany severe GERD." That motility point has a surgical consequence: absent contractility is, for most patients, a contraindication to fundoplication, which is why manometry precedes every antireflux operation. When contact outlasts the defenses, the mucosa fails in layers: the pre-epithelial barrier (unstirred water layer and bicarbonate) is compromised, epithelial tight junctions and buffers weaken, blood supply falls, and histology shows dilated intercellular spaces, basal-cell hyperplasia, and neutrophils. The injury is not purely chemical — reflux activates HIF-2α and NF-κB, recruiting pro-inflammatory cytokines and T cells, so esophagitis is an inflammatory disease that acid starts.

GERD comes in three phenotypes. Nonerosive reflux disease (NERD) means symptoms with no mucosal damage (a valid label only if the endoscopy was done off PPIs); erosive esophagitis means visible erosions or ulcers, graded Los Angeles A through D by the length and circumference of the mucosal breaks; Barrett esophagus means the squamous lining has been replaced. PPIs relieve symptoms in about 50–60% of NERD patients versus 70–80% of erosive disease — a reminder that the worst-looking esophagus is often the most drug-responsive.

Chronic, untreated esophagitis climbs a ladder. Persistent inflammation lays down fibrosis and narrows the lumen into a peptic stricture — 70–80% of adult benign esophageal strictures — announced by progressive dysphagia to solids, then semisolids, then liquids. Or the mucosa adapts: squamous epithelium is replaced by columnar epithelium with goblet cells (intestinal metaplasia), a tissue "more resistant to acid exposure but [that] can become cancerous." That is Barrett esophagus, present in roughly 5–12% of chronic-GERD patients — about 1 in 10 — and it usually causes no symptoms of its own. Barrett’s progresses through low-grade and high-grade dysplasia to esophageal adenocarcinoma; nondysplastic Barrett’s advances at well under 1% per year (roughly 0.1–0.5%), low-grade dysplasia at about 0.7% per year (ACG 2022), and more than 95% of Barrett’s patients never develop cancer. The ladder is why alarm symptoms skip the PPI trial and go straight to the scope.

Refluxate that climbs past the upper esophagus produces the extraesophageal syndromes: chronic cough, wheezing, new or worsened asthma, laryngitis and hoarseness, sore throat, chronic throat-clearing, a postnasal-drip sensation, laryngospasm, and dental erosions as acid dissolves enamel. Cough is explained by an esophageal–bronchial vagal reflex or by direct irritation of the pharynx and larynx. The asthma link may run both ways: increased vagal tone and negative intrathoracic pressure during asthma promote reflux, and asthma drugs such as theophylline and β-agonists lower LES pressure — so association and causation stay tangled. Laryngopharyngeal reflux ("silent reflux") often lacks heartburn entirely, hoarseness is near-universal, and the laryngoscopic "reflux" signs turn up in 86–93% of asymptomatic volunteers — ACG 2022 warns the diagnosis must never rest on laryngoscopy alone. It also warns that PPIs fail to fix chronic cough in most patients and show no asthma-control benefit in trials, so extraesophageal symptoms without typical heartburn get reflux testing before a PPI, not an empiric prescription.

The trap that matters most at the bedside is noncardiac chest pain. Reflux "may mimic cardiac pain," and the professional rule is unambiguous: "when the presenting symptom is chest pain, cardiac disease must first be excluded before performing gastrointestinal evaluation or planning for a prolonged trial of medication." The comparison the nurse holds in mind is the ischemic profile — retrosternal or high-epigastric, nonstabbing, persistent for at least 20 minutes at rest, and not triggered by respiration, movement, or palpation — with the caveat that acute coronary syndrome "may present atypically in patients with diabetes, lacking chest pain and instead manifesting with marked malaise." Exclusion runs on the ECG integrated with symptom timing and high-sensitivity troponin, never on whether an antacid helped: clinical features alone are insufficient, and response to a GI medication is not a discriminator. Patient teaching makes the same point: burning chest pain that feels crushing, or chest pain with shortness of breath or jaw or arm pain, may be a heart attack and needs emergency help — not an antacid and a wait.