Acid Reflux (GERD) — Causes, Symptoms, Diagnosis & Treatment Guide — Symptoms, Causes & Treatment | MyMedicPlus

Gastro-oesophageal reflux disease (GERD) — also called acid reflux disease — occurs when stomach acid and/or contents flow back (reflux) into the oesophagus repeatedly, causing troublesome symptoms and/or oesophageal mucosal damage. It is one of the most common chronic gastrointestinal conditions, affecting approximately 20% of adults in Western countries, with rising prevalence globally driven by increasing obesity rates. GERD is defined by the Montreal Consensus (2006) as a condition where reflux causes troublesome symptoms or complications. The spectrum ranges from non-erosive reflux disease (NERD — symptoms without visible mucosal damage, the most common form) to erosive oesophagitis (visible mucosal breaks on endoscopy), Barrett's oesophagus (metaplastic change of the oesophageal lining, a pre-cancerous condition), and oesophageal adenocarcinoma (the most serious complication, incidence rising in Western countries).

GERD results from dysfunction of the lower oesophageal sphincter (LOS) — the muscle valve separating the oesophagus from the stomach. LOS relaxations, reduced resting LOS tone, or impaired oesophageal clearance allow acid exposure. Hiatus hernia (the stomach herniating through the diaphragm) is present in approximately 50% of GERD patients and compromises the physiological anti-reflux barrier. Risk factors: obesity (abdominal fat increases intra-gastric pressure — the strongest modifiable risk factor, with a 2.5x risk at BMI over 30); pregnancy (progesterone relaxes the LOS); smoking (reduces LOS tone); alcohol; caffeine and certain foods (chocolate, peppermint, spicy and fatty foods, citrus, tomato); hiatus hernia; scleroderma (impaired oesophageal peristalsis); and medications that reduce LOS tone (calcium channel blockers, nitrates, theophylline, anticholinergics, bisphosphonates — which can also cause direct oesophageal injury).

Classic oesophageal symptoms: heartburn (burning sensation in the central chest or epigastrium, radiating upward — typically worse after meals, lying down, or bending forward) and regurgitation (effortless return of acid or food contents into the mouth or throat). Dysphagia (difficulty swallowing) suggests oesophageal stricture, severe oesophagitis, or malignancy — requires urgent investigation. Atypical (extra-oesophageal) GERD symptoms: chronic non-productive cough (10-40% of chronic cough is GERD-related), hoarseness (laryngopharyngeal reflux), chronic sore throat, globus sensation (lump in the throat), dental erosion (from acid contact), worsening asthma (acid aspiration or vagally-mediated bronchoconstriction), and non-cardiac chest pain (GERD is the most common cause of non-cardiac chest pain — always exclude cardiac origin first). Alarm features requiring urgent endoscopy: dysphagia, odynophagia (painful swallowing), unexplained weight loss, vomiting, anaemia, haematemesis (vomiting blood), and onset of symptoms over 55 years.

Typical GERD symptoms in a patient under 55 without alarm features can be diagnosed clinically — a trial of proton pump inhibitor (PPI) therapy is both diagnostic and therapeutic. Upper GI endoscopy (OGD) is indicated for: alarm features (dysphagia, weight loss, anaemia, haematemesis, odynophagia); age over 55 with new or recent-onset symptoms; symptoms persisting despite adequate PPI therapy; and Barrett's oesophagus surveillance. Endoscopy grades oesophagitis severity (Los Angeles classification A-D) and identifies Barrett's oesophagus, peptic ulcer disease, or malignancy. 24-hour ambulatory oesophageal pH monitoring (pH-impedance testing) is the gold standard for confirming pathological acid exposure and correlating symptoms with reflux events — used when diagnosis is uncertain, symptoms persist despite PPI, or before anti-reflux surgery. Oesophageal manometry assesses LOS pressure and oesophageal peristalsis — essential before surgical planning.

Lifestyle modifications: weight loss (BMI reduction of 3.5 kg/m² reduces GERD symptoms significantly); elevate the head of the bed 15-20 cm (reduces nocturnal reflux); avoid meals within 3 hours of bedtime; reduce portion sizes; avoid alcohol, caffeine, fatty and spicy foods, and tobacco. Medications — Proton pump inhibitors (PPIs): omeprazole 20mg, lansoprazole 30mg, esomeprazole 20-40mg — taken 30-60 minutes before breakfast; most effective acid suppressants available, healing oesophagitis in 85-95% within 4-8 weeks. H2 receptor antagonists (H2RAs): ranitidine (withdrawn), famotidine — less effective than PPIs but useful as add-on for nocturnal symptoms. Alginate-containing antacids (Gaviscon): useful for post-prandial reflux. PPIs should be used at the lowest effective dose for symptom control. Anti-reflux surgery: laparoscopic Nissen fundoplication (wrapping the fundus of stomach around the lower oesophagus to recreate the anti-reflux barrier) is highly effective for carefully selected patients with confirmed GERD who prefer surgery to lifelong medication, or those with large hiatus hernia. LINX device (magnetic sphincter augmentation) is an alternative minimally invasive option.

Untreated or inadequately controlled GERD can progress to several serious complications. Barrett's oesophagus develops in approximately 10-15% of patients with chronic GERD — the normal squamous oesophageal epithelium is replaced by metaplastic columnar epithelium (intestinal metaplasia) from chronic acid injury, increasing oesophageal adenocarcinoma risk by 30-fold and requiring endoscopic surveillance every 2-5 years. Oesophageal stricture (peptic stricture) forms in 10-15% of patients from fibrous scarring — causing progressive dysphagia requiring repeated endoscopic dilatation. Erosive oesophagitis causes bleeding, odynophagia, and iron-deficiency anaemia from chronic blood loss. Oesophageal adenocarcinoma — arising in Barrett's — carries a 5-year survival of only 15-20% and is the fastest-rising cancer in incidence in many high-income countries. Respiratory complications include chronic cough, worsening of asthma (in approximately 70% of asthmatics with GERD), and aspiration pneumonia from nocturnal refluxate. Dental erosion from acid exposure, laryngitis, and chronic sinusitis are additional complications of uncontrolled GERD.

Weight loss to a healthy BMI is the most impactful preventive measure — reducing both the frequency and severity of GERD symptoms. Avoid postprandial lying down and large evening meals. Elevate the head of the bed for nocturnal symptoms. Smoking cessation reduces LOS dysfunction and oesophageal exposure to carcinogens. Barrett's oesophagus surveillance: patients with confirmed Barrett's require endoscopic surveillance every 2-5 years (depending on segment length and dysplasia) to detect early oesophageal adenocarcinoma — when high-grade dysplasia is identified, endoscopic ablation (radiofrequency ablation) is highly effective at eliminating the pre-malignant tissue. Avoid unnecessary long-term PPI use — recent concerns about microbiome changes, hypomagnesaemia, vitamin B12 deficiency, and C. difficile risk require periodic reassessment of the need for continued therapy.

See your GP promptly if you experience: difficulty or pain on swallowing (dysphagia or odynophagia); unexplained weight loss alongside reflux symptoms; vomiting of blood or coffee-ground material; black tarry stools; iron deficiency anaemia; or onset of significant reflux symptoms over age 55. These alarm features require urgent endoscopy to exclude oesophageal cancer, Barrett's oesophagus, peptic ulceration, or other serious pathology. Also see a doctor if heartburn is severe, occurring daily, and not adequately controlled with over-the-counter antacids or H2 blockers. Chest pain that may be cardiac must be urgently assessed before assuming a gastrointestinal cause — call emergency services if chest pain is severe, associated with sweating, or radiating to the jaw or arm.