Conditions That Disguise Themselves as Ordinary Indigestion

Gastroesophageal reflux disease (GERD) occurs when stomach acid flows back into the esophagus more frequently than normal, irritating its lining. The hallmark symptom is heartburn — a burning sensation rising from the chest — but many people with GERD primarily notice upper abdominal discomfort, bloating, or a sour taste, all of which read as plain indigestion.

GERD is one of the most commonly missed mimics because occasional acid reflux is so normal that people rarely flag it. Over time, untreated GERD can damage the esophageal lining. To understand just how convincingly GERD can disguise itself, see our detailed explanation of what GERD is and why it can feel like a heart attack.

Peptic ulcers are open sores that develop on the lining of the stomach or the upper part of the small intestine (the duodenum). They are most often caused by infection with the bacterium Helicobacter pylori or by long-term use of nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen.

The pain — typically a gnawing or burning sensation in the upper abdomen — often improves temporarily after eating or taking antacids, which is precisely why it gets dismissed as indigestion. Some ulcers cause no pain at all until a complication, such as bleeding, develops. A simple breath or stool test can detect H. pylori infection, and treatment is highly effective once the correct diagnosis is made.

The gallbladder sits just below the liver and stores bile used to digest fats. When gallstones form or the gallbladder becomes inflamed, the resulting discomfort — typically in the upper right or upper middle abdomen — can feel strikingly similar to indigestion, particularly after fatty meals.

Episodes may last from minutes to a few hours before resolving, reinforcing the impression that it was simply something eaten. However, gallbladder attacks tend to be more intense than routine indigestion and may radiate to the right shoulder or back. An ultrasound is the standard first test used to identify gallstones.

Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder — meaning the gut appears structurally normal but does not work as expected. Symptoms include abdominal cramping, bloating, gas, and altered bowel habits (diarrhea, constipation, or both), all of which can be interpreted as persistent indigestion.

Because IBS has no single definitive diagnostic test, reaching a diagnosis requires ruling out other conditions. Many people live with IBS for years before it is identified. If you're trying to understand how IBS differs from inflammatory bowel conditions, our article on IBS, IBD, and Crohn's disease explains the key distinctions.

Celiac disease is an autoimmune condition in which consuming gluten — a protein found in wheat, barley, and rye — triggers an immune response that damages the small intestine's lining. Digestive symptoms such as bloating, gas, abdominal pain, and diarrhea are common, but some individuals experience primarily nausea and upper abdominal discomfort that mimics indigestion.

Celiac disease is significantly underdiagnosed; according to the National Institutes of Health, it is estimated to affect roughly 1 in 133 Americans, yet the majority remain undiagnosed. Blood tests screening for specific antibodies, followed by an intestinal biopsy if indicated, are the standard diagnostic pathway. A gluten-free diet remains the cornerstone of management, but self-diagnosis without testing is discouraged.

Gastroparesis is a condition in which the stomach empties more slowly than normal, without any physical obstruction. The nerve signals that coordinate stomach muscle contractions are impaired. Symptoms — nausea, bloating, early fullness, and upper abdominal discomfort — are indistinguishable from indigestion based on experience alone.

Gastroparesis is more common in people with diabetes, though it can occur without any underlying condition. It is diagnosed through a gastric emptying study, a test that tracks how quickly food moves through the stomach. Because its symptoms overlap so broadly with other digestive conditions, multiple alternative diagnoses are often explored before gastroparesis is confirmed.