What Can Be Mistaken for Acid Reflux? 11 Conditions

Several serious and not-so-serious conditions produce symptoms nearly identical to acid reflux, including burning chest pain, regurgitation, and difficulty swallowing. The overlap is so thorough that some of these conditions go misdiagnosed for months or years, treated with acid-suppressing drugs that never fully work because stomach acid was never the core problem. Knowing what else can cause that familiar burning sensation changes when you push for further testing and when you accept the antacid and move on.

Eosinophilic Esophagitis

Eosinophilic esophagitis, often shortened to EoE, is one of the conditions most commonly confused with acid reflux. It causes heartburn, chest pain, and trouble swallowing, and it does not respond to standard acid-suppressing medications the way true reflux does.¹ EoE is driven by an immune reaction in the esophagus, typically triggered by food allergens, rather than by acid washing upward from the stomach. White blood cells called eosinophils build up in the esophageal lining, causing inflammation and narrowing.

The hallmark clue is food getting stuck. While acid reflux can make swallowing uncomfortable, EoE frequently causes food to lodge in the esophagus, sometimes requiring emergency removal. If you have been diagnosed with reflux but your heartburn barely budges on proton pump inhibitors, and you occasionally feel food stalling on the way down, EoE is worth investigating. Diagnosis requires an endoscopy with tissue biopsies; the esophagus often shows characteristic ring-like ridging.

Achalasia

Achalasia is an esophageal motility disorder in which the lower esophageal sphincter fails to relax properly during swallowing. Food and liquid collect in the esophagus instead of passing smoothly into the stomach. The result feels remarkably like reflux: patients report heartburn and regurgitation, and the diagnosis is frequently delayed because those symptoms get chalked up to garden-variety acid reflux.²

The difference is mechanical. In reflux, the sphincter is too loose, letting acid splash upward. In achalasia, the sphincter is too tight, trapping food above it. The regurgitated material tastes different too: in achalasia it tends to be undigested and bland rather than sour or bitter, because it never reached the stomach in the first place. Progressive difficulty swallowing both solids and liquids, along with unintentional weight loss, should raise suspicion. Specialized pressure testing of the esophagus, called manometry, is the gold-standard diagnostic tool.

Gastroparesis

When the stomach empties too slowly, the food that lingers creates pressure that can push contents back up toward the esophagus. Gastroparesis causes nausea, vomiting, bloating, and regurgitation that overlap heavily with acid reflux symptoms.³ In a large study of over 400 gastroparesis patients, roughly a quarter reported moderate to very severe heartburn and regurgitation.⁴

Gastroparesis and reflux can also coexist, which muddies the picture further. The delayed emptying raises pressure inside the stomach and increases the volume of material available to reflux.³ If your reflux symptoms are accompanied by early fullness after meals, persistent nausea, or vomiting of food eaten hours earlier, gastroparesis may be part of the equation. A gastric emptying study, where you eat a meal tagged with a small amount of radioactive material and sit under a scanner, can confirm whether your stomach empties at a normal rate.

Functional Heartburn and Reflux Hypersensitivity

Some people experience textbook reflux symptoms, including burning and regurgitation, yet when doctors test their esophagus, acid exposure is completely normal. This is the territory of functional heartburn and a related condition called reflux hypersensitivity. In reflux hypersensitivity, the esophagus overreacts to tiny amounts of acid that would not bother most people, generating pain and burning from exposures that fall within the normal range.⁵

Functional heartburn goes a step further: the symptoms have no measurable connection to any reflux event at all. Both conditions look identical to ordinary reflux from the patient’s perspective, and proton pump inhibitors provide little or no relief because acid production is not the real issue. Treatment usually shifts toward medications that target nerve sensitivity and pain processing, along with behavioral approaches. These diagnoses tend to come after extensive testing rules out structural and chemical causes, so they are often called diagnoses of exclusion.

Pill-Induced Esophagitis

Certain medications can injure the esophageal lining directly if they dissolve or lodge partway down. The resulting inflammation produces chest pain, heartburn, and painful swallowing that feel indistinguishable from acid reflux. Antibiotics and nonsteroidal anti-inflammatory drugs like ibuprofen and naproxen are the most common culprits.⁶ Bisphosphonates used for osteoporosis and potassium supplements are also well-known offenders.

The damage can be surprisingly severe. Endoscopic studies of pill-induced esophagitis find ulcers in most cases, with erosion and even active bleeding in a smaller proportion.⁶ The giveaway is timing: if your “reflux” appeared shortly after starting a new medication, or if it worsens specifically when you take pills without enough water or right before lying down, pill-induced injury is a strong possibility. Swallowing medications with a full glass of water and remaining upright for at least 30 minutes afterward goes a long way toward prevention.

Costochondritis and Musculoskeletal Chest Pain

The chest wall itself can generate burning or aching pain that patients assume is coming from their esophagus or stomach. Costochondritis, an inflammation of the cartilage connecting the ribs to the breastbone, is one of the most common causes of non-cardiac chest pain. The discomfort typically sits in the center of the chest, can worsen after meals because of the mechanical pressure of a full stomach pressing outward, and sometimes radiates in a pattern that feels like heartburn.

The key distinguishing feature is reproducibility with movement or touch. If pressing on the front of your ribcage reproduces the pain, or if the discomfort changes when you twist, stretch, or take a deep breath, the source is likely musculoskeletal rather than esophageal. Reflux pain generally does not change with physical position or chest compression. Costochondritis is self-limiting and usually resolves with anti-inflammatory medication and time, though the irony is that the NSAIDs used to treat it can themselves irritate the esophagus if taken carelessly.

Heart Disease

This is the mimic that matters most, because the consequences of a missed diagnosis are the most severe. Angina, the chest pain caused by reduced blood flow to the heart, can present as a burning sensation in the center of the chest that patients describe in nearly the same language they would use for heartburn. Heart attacks, too, sometimes produce burning rather than the classic crushing pressure. A case report of a large diaphragmatic hernia illustrates how easily the wires get crossed: a patient presented with chest pain radiating to the left shoulder and breathlessness, was initially investigated for a cardiac problem, and turned out to have a structural issue near the esophagus entirely.⁷

The diagnostic confusion runs in both directions: heart disease gets mistaken for reflux, and reflux gets mistaken for heart disease. A few red flags point toward the heart rather than the esophagus. Pain triggered by physical exertion rather than meals, pain radiating to the arm or jaw, associated shortness of breath, lightheadedness, or cold sweats all warrant immediate medical evaluation. When in doubt, err on the side of the emergency room. Antacids are forgiving of a wrong guess; an untreated heart attack is not.

Paraesophageal Hernia

Most people have heard of a hiatal hernia, where a portion of the stomach pushes up through the diaphragm. A paraesophageal hernia is a specific and sometimes more dangerous variant in which the stomach (or occasionally other organs) herniates alongside the esophagus through the diaphragmatic opening. These hernias produce chest pain, postprandial discomfort, regurgitation, and a sensation of fullness that overlap directly with acid reflux symptoms.⁷

Small sliding hiatal hernias are extremely common and often do genuinely contribute to reflux, so they are treated with standard acid suppression. Larger paraesophageal hernias, however, may need surgical repair because of the risk of the herniated stomach becoming trapped or losing its blood supply. If reflux symptoms are accompanied by a feeling of chest pressure after eating, early satiety, or intermittent breathlessness, imaging can determine whether a significant hernia is present.

Systemic Sclerosis (Scleroderma)

Scleroderma is an autoimmune condition that hardens and tightens connective tissue throughout the body. The esophagus is the most commonly affected part of the gastrointestinal tract, with esophageal involvement occurring in roughly 80% of scleroderma patients.⁸ The disease progressively replaces the smooth muscle of the esophagus with fibrous scar tissue, weakening the lower esophageal sphincter and crippling the peristaltic waves that normally push food downward.⁹

The resulting symptoms are a mixture of true reflux (because the weakened sphincter does let acid through) and dysmotility (because the esophagus cannot clear that acid efficiently). Pressure testing finds the classic scleroderma pattern, absent or ineffective peristalsis in the lower esophagus combined with a weak sphincter, in over half of patients studied.¹⁰ The esophageal symptoms may appear early in the disease, sometimes before other signs like skin thickening become obvious. Aggressive acid suppression is warranted in scleroderma because the esophagus’s inability to clear acid puts patients at high risk for complications like strictures and Barrett’s esophagus.

Vocal Cord Dysfunction

Vocal cord dysfunction is a condition in which the vocal cords close when they should open, particularly during inhalation. It causes throat tightness, coughing, hoarseness, and a choking sensation that can overlap with the throat-focused symptoms of acid reflux, sometimes called laryngopharyngeal reflux. The relationship between the two conditions is tangled: reflux can actually trigger vocal cord dysfunction episodes, so they often coexist. In one study of patients referred to a specialized vocal cord dysfunction clinic, over 80% had confirmed reflux disease.¹¹

The complicating twist is that treating the reflux alone does not reliably fix the vocal cord problem. In that same study, only about a quarter of patients saw improvement in their vocal cord dysfunction attacks after eight weeks of acid suppression.¹¹ If your primary complaints are throat tightness, noisy breathing, or a feeling of the airway closing, especially during exercise or stress, vocal cord dysfunction deserves separate evaluation. Speech therapy techniques that retrain breathing patterns are the standard treatment, distinct from anything used for reflux.

Bile Reflux

Acid reflux gets all the attention, but bile can wash backward into the stomach and esophagus too. Bile reflux produces a burning sensation, nausea, and a distinctively bitter taste that overlaps heavily with acid reflux. It is especially common after certain surgeries. Patients who have had their gallbladder removed appear predisposed to bile reflux gastritis, experiencing abdominal pain, bloating, heartburn, and that characteristic bitter taste.¹²

The practical problem is that proton pump inhibitors, which work by reducing acid production, do not address bile. If you have persistent burning and nausea that do not improve with acid suppression, particularly after gallbladder removal or other upper gastrointestinal surgery, bile reflux should be considered. Bile-binding agents like cholestyramine and certain medications that promote gastric motility are used instead of or alongside standard acid-reducing drugs. Endoscopy can sometimes reveal the telltale sign of bile pooling in the stomach.

Functional Chest Pain and Esophageal Hypersensitivity

Functional chest pain used to be treated as primarily a psychological problem, but research over the past two decades has reframed it. Many patients with unexplained chest pain that looks like reflux actually have heightened nerve sensitivity in the esophagus, a condition called visceral hyperalgesia. Their esophageal nerves fire pain signals in response to stimuli, like minor stretching or tiny amounts of acid, that would go unnoticed in most people.¹³

The pain can be severe enough to send people to the emergency room convinced they are having a heart attack. Standard reflux testing comes back normal. Cardiac workups come back normal. Patients sometimes cycle through both gastroenterology and cardiology without getting a clear answer. Treatment focuses on the nervous system rather than the gut: low-dose antidepressants that modulate pain signaling, cognitive behavioral therapy, and in some cases esophageal-directed hypnotherapy have shown benefit. Recognizing this as a nerve-sensitivity issue rather than a mysterious absence of findings tends to be therapeutic in itself, because it replaces diagnostic limbo with a treatable framework.

When the Standard Medications Do Not Work

The thread running through all eleven of these conditions is that they tend to surface clinically when acid-suppressing medication fails. A trial of proton pump inhibitors is often the first step in managing suspected reflux, and when it works, the question of what else it might be rarely comes up. The diagnostic search begins in earnest when symptoms persist despite adequate acid suppression, when symptoms have unusual features like food impaction or weight loss, or when alarm signs appear.

Alarm features that should prompt further investigation include difficulty swallowing that is getting worse over time, unintentional weight loss, vomiting blood or passing black stools, chest pain with exertion, and new onset of symptoms after age 50. None of these necessarily mean something dangerous is happening, but they shift the probability enough to justify endoscopy, motility testing, imaging, or cardiac evaluation rather than another round of the same medication. The most common mistake patients make is assuming that reflux is the only explanation for a burning chest, continuing to self-treat with over-the-counter acid reducers for months without reassessing. If the pills are not working, the diagnosis may need revising.

Overlap and Coexistence

Real clinical presentations are messier than a list of eleven separate diagnoses suggests. Many of these conditions coexist with genuine acid reflux rather than simply mimicking it. Gastroparesis worsens reflux by keeping food in the stomach longer. Scleroderma causes both true reflux and motility problems simultaneously. Vocal cord dysfunction is triggered by reflux episodes. Paraesophageal hernias mechanically disrupt the anti-reflux barrier. In these cases, acid-suppressing medication may partially help but leaves a residual layer of symptoms that requires condition-specific treatment.

This is part of why “refractory reflux,” the clinical term for reflux that does not respond to medication, has become an area of active research. Among patients labeled as having treatment-resistant reflux, a substantial proportion turn out to have one of the conditions described here rather than true acid reflux that is simply stubborn. Getting the right diagnosis often means moving beyond empirical acid suppression and into targeted testing: manometry for motility problems, pH monitoring for functional heartburn, endoscopy with biopsies for eosinophilic esophagitis, gastric emptying studies for gastroparesis, or laryngoscopy for vocal cord dysfunction. Each condition has its own diagnostic pathway, and each has treatments that differ meaningfully from the standard reflux playbook.

1
PubMed. Eosinophilic esophagitis: an increasingly recognized cause of dysphagia, food impaction, and refractory heartburn
2
PubMed Central. Is Gastroesophageal Reflux Disease and Achalasia Coincident or Not?
3
PubMed Central. Treatment Challenges in the Management of Gastroparesis-Related GERD
4
PubMed. Reflux Symptoms in Gastroparesis: Correlation With Gastroparesis Symptoms, Gastric Emptying, and Esophageal Function Testing
5
Gut and Liver. Esophageal Reflux Hypersensitivity: A Comprehensive Review
6
International Journal of Basic & Clinical Pharmacology. Clinical and endoscopic features of pill-induced esophagitis
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PubMed Central. Transthoracic repair of paraesophageal diaphragmatic hernia presenting with symptoms mimicking cardiac disease (chest pain and breathlessness)
8
PubMed. Esophageal dysmotility associated with systemic sclerosis: a high-resolution manometry study
9
PubMed Central. Esophageal manifestation in patients with scleroderma
10
PubMed Central. Evaluation and management of esophageal manifestations in systemic sclerosis
11
PubMed. Acid suppression does not reduce symptoms from vocal cord dysfunction, where gastro-laryngeal reflux is a known trigger
12
PubMed Central. Rabeprazole combined with hydrotalcite is effective for patients with bile reflux gastritis after cholecystectomy
13
Gastroenterology. Functional chest pain: nociception and visceral hyperalgesia