Indigestion, medically known as dyspepsia, is a common experience involving discomfort in the upper abdomen. This discomfort often manifests as an uncomfortable feeling of fullness after eating or a painful burning sensation in the upper belly. While SARS-CoV-2 is primarily known for respiratory symptoms, it is recognized that the virus can affect multiple body systems, including the digestive tract. This connection means that indigestion may occur as a symptom of COVID-19, though it is far more often related to non-infectious causes.
Gastrointestinal Manifestations of COVID-19
Indigestion is one of a spectrum of gastrointestinal (GI) issues observed in people with COVID-19. Studies show that GI symptoms are a recognized manifestation, appearing in an estimated 10% to 50% of confirmed cases. These symptoms often include nausea, vomiting, loss of appetite, and diarrhea, alongside upper abdominal pain or discomfort.
For some individuals, these digestive issues may not only accompany typical respiratory symptoms but may also be the first sign of infection. In a smaller subset of patients, GI problems can even be the only noticeable symptom of COVID-19, which complicates diagnosis. The prevalence of abdominal pain or epigastric discomfort is reported to range from approximately 2% to 14% among COVID-19 patients. Recognizing this broad range of symptoms suggests the virus is not solely a respiratory pathogen.
How SARS-CoV-2 Impacts the Digestive Tract
SARS-CoV-2 is able to directly infect the cells lining the digestive system, providing a biological explanation for these symptoms. The virus uses a surface protein to bind to the Angiotensin-Converting Enzyme 2 (ACE2) receptor on human cells for entry. These ACE2 receptors are highly abundant on enterocytes, the absorptive cells found in the lining of the small intestine and colon.
The concentration of ACE2 receptors in the intestines is significantly higher than in the lungs, making the digestive tract a prime site for viral entry and replication. When the virus binds to these cells, it causes direct damage to the gut lining and subsequent inflammation. This local inflammation and resulting dysfunction in the intestinal barrier are thought to drive symptoms like pain and vomiting. The infection can also disrupt the balance of the gut microbiome, which may contribute to persistent digestive issues after the acute illness has passed.
Common Causes of Indigestion That Are Not COVID-19
Most cases of indigestion are not related to a viral infection but rather to common, non-infectious conditions. Functional dyspepsia is the most frequent diagnosis, accounting for the majority of chronic indigestion cases where no specific underlying disease is found. This condition is characterized by upper abdominal pain or discomfort, often linked to impaired stomach motility or hypersensitivity to normal digestive processes.
Other frequent causes fall under the category of “organic dyspepsia,” meaning a specific, identifiable cause is present. Gastroesophageal Reflux Disease (GERD), or chronic acid reflux, is a major culprit, causing heartburn and regurgitation. Peptic ulcers and gastritis, inflammation of the stomach lining, are also common triggers, sometimes worsened by nonsteroidal anti-inflammatory drugs (NSAIDs). Indigestion caused by these non-viral issues rarely includes systemic symptoms like fever, body aches, or loss of taste and smell that usually accompany a viral infection.
When to Test and Seek Medical Consultation
People experiencing indigestion should consider the context of their symptoms to determine the appropriate next step. If new-onset indigestion is accompanied by classic COVID-19 symptoms, such as fever, persistent cough, or loss of taste or smell, testing for SARS-CoV-2 is advised. If you have been exposed to a confirmed case but are asymptomatic, wait at least five full days after exposure before testing for the most accurate results.
Seek immediate medical attention if indigestion is accompanied by severe warning signs, as these may indicate a serious complication. These red-flag symptoms include severe abdominal pain, difficulty breathing, bloody or black, tarry stools, or persistent vomiting. For general indigestion that is not severe but lasts for more than a few days or recurs frequently, consulting a healthcare provider is prudent to identify the underlying cause.