Acid reflux happens when stomach acid flows backward into the esophagus, the tube connecting your mouth to your stomach. Nearly everyone experiences it occasionally, but roughly 18 to 28% of adults in North America deal with it frequently enough to qualify as a chronic condition called gastroesophageal reflux disease, or GERD. The difference comes down to frequency: occasional episodes are normal, while symptoms occurring two or more times per week, or acid exposure that damages esophageal tissue, cross into GERD territory.
How the Anti-Reflux Barrier Works
At the bottom of your esophagus sits a ring of muscle called the lower esophageal sphincter (LES). It opens to let food pass into your stomach, then closes to keep stomach contents from traveling back up. A section of the diaphragm called the crura wraps around this area and acts as a second layer of defense, squeezing the junction shut when you bend over, cough, or strain.
Acid reflux occurs when this barrier fails. The most common cause is transient relaxations of the LES, moments when the sphincter opens spontaneously without any swallowing involved. People with frequent reflux tend to have these relaxations more often than normal. The second pattern is chronically weak resting pressure in the sphincter itself, which allows acid to seep through more easily. Both patterns appear to stem primarily from faulty nerve signaling to the muscle rather than a structural defect in the muscle itself.
The Role of Hiatal Hernia
A hiatal hernia occurs when the upper portion of the stomach pushes up through the opening in the diaphragm where the esophagus passes through. This disrupts the anti-reflux barrier in several ways at once: it shortens the sphincter and reduces its pressure, it prevents the diaphragm from reinforcing the seal, it weakens the wave-like contractions that normally push acid back down, and it creates a small pocket above the diaphragm where acid can pool and reflux into the esophagus during swallowing. Not everyone with a hiatal hernia develops significant reflux, but the anatomical disruption makes it considerably more likely.
Common and Overlooked Symptoms
The hallmark symptoms are familiar: a burning sensation behind the breastbone (heartburn) and the taste of acid or partially digested food rising into the throat. These tend to worsen after meals, when lying down, or when bending forward.
Less obvious symptoms catch many people off guard. Acid vapor can reach the throat and voice box, causing chronic hoarseness, frequent throat clearing, a sore or burning throat, and difficulty swallowing. A persistent cough that doesn’t respond to typical cold or allergy treatments is another common sign. Some people develop a sensation called globus, a feeling of a lump or choking in the throat that’s most noticeable between meals and tends to disappear at night. Reflux accounts for 25 to 50% of globus cases. In some instances, reflux can trigger or worsen asthma symptoms or cause chest pain that mimics a heart problem.
What Triggers Episodes
Certain foods and drinks directly weaken sphincter pressure or increase acid production. High-fat meals, alcohol, chocolate, and carbonated beverages all reduce sphincter pressure and increase the amount of time acid sits in the esophagus. Mint and caffeinated drinks have a similar relaxing effect on the sphincter. Spicy foods, citrus fruits, tomatoes, onions, and garlic don’t necessarily weaken the sphincter but can irritate already-inflamed tissue, making symptoms feel worse.
Beyond diet, eating large meals, lying down within two to three hours of eating, smoking, and excess weight around the midsection all increase reflux risk. Tight clothing around the waist can add enough abdominal pressure to push acid upward.
How It’s Diagnosed
Most people with classic heartburn symptoms are diagnosed based on their history alone, sometimes with a trial of acid-reducing medication to see if symptoms improve. When symptoms are unusual, persistent, or don’t respond to treatment, more specific testing comes into play.
The most direct measurement involves monitoring the pH (acidity level) inside the esophagus over an extended period. A small wireless capsule can be temporarily attached to the esophageal lining, recording acid exposure for 48 hours as you go about your daily routine. This is more informative than older catheter-based tests that only recorded for 24 hours. An upper endoscopy, where a thin camera is passed down the throat, lets a gastroenterologist visually inspect the esophageal lining for inflammation, narrowing, or cellular changes.
Lifestyle Changes That Help
Sleep position makes a measurable difference. Lying on your right side places your esophagus below the junction with the stomach, essentially letting acid pool at the entrance. Sleeping on your left side does the opposite, positioning the esophagus above the stomach so gravity works in your favor. Elevating the head of your bed by six to eight inches (using a wedge or bed risers, not just extra pillows) provides an additional gravity advantage throughout the night.
Eating smaller meals, finishing dinner at least two to three hours before bed, and losing excess abdominal weight all reduce the mechanical pressure that pushes acid upward. Identifying your personal trigger foods through an elimination approach tends to be more effective than following a generic “avoid” list, since triggers vary widely from person to person.
How Medications Work
Three classes of medication target reflux, each working differently.
- Antacids neutralize acid already present in the stomach. They provide the fastest relief, often within minutes, but their effect is short-lived and they do nothing to prevent future acid production.
- H2 blockers reduce acid secretion by blocking one of the chemical signals that tell stomach cells to produce acid. They keep stomach acidity low for roughly four hours per dose and work well for mild, predictable symptoms.
- Proton pump inhibitors (PPIs) shut down the acid-producing pumps inside stomach cells directly. They’re the most powerful option, maintaining reduced acidity for 15 to 22 hours per day. Because they have a short window of activity in the body (a half-life of about 30 minutes to two hours), timing matters: they work best taken 30 to 60 minutes before a meal.
PPIs are significantly more effective for healing damaged esophageal tissue. In studies of ulcer healing, PPIs achieved healing rates around 96% at eight weeks compared to 57% for H2 blockers over the same period. For occasional symptoms, antacids or H2 blockers are usually sufficient. For frequent or erosive reflux, PPIs are the standard approach.
Long-Term Risks of Untreated Reflux
Chronic acid exposure can gradually change the cells lining the lower esophagus, a condition called Barrett’s esophagus. The normal flat cells are replaced by taller, column-shaped cells more typical of the intestinal lining. Barrett’s itself doesn’t cause symptoms beyond the reflux that triggered it, but it’s considered a precancerous condition. The risk of those abnormal cells progressing to esophageal cancer is roughly 0.5% per year, or about 5 to 6 cases per 1,000 patients annually. That’s low on an individual basis, but it’s the reason people with long-standing, severe reflux are often screened with periodic endoscopy.
Other complications of persistent, untreated reflux include esophageal strictures (scarring that narrows the esophagus and makes swallowing difficult), chronic inflammation, and dental enamel erosion from repeated acid exposure in the mouth.