Gastritis-I: Introduction and Types

Gastritis is inflammation of the stomach lining, also called the gastric mucosa. It occurs when the stomach's protective barrier is disrupted, reducing mucus secretion or decreasing blood flow to the mucosa. This condition can develop suddenly or gradually depending on the type and underlying cause.

Gastritis is classified into three primary types: acute gastritis, a transient inflammation triggered by corrosive agents, medications, alcohol, or infections; chronic gastritis, which develops gradually and persists for months to years if untreated, often caused by Helicobacter pylori infection or autoimmune disorders; and reactive gastritis, characterized by mild inflammation from prolonged drug use, alcohol, or radiation exposure.

Acute gastritis results from various stressors including corrosive agents, medications like digoxin, alcohol consumption, gastric radiation therapy, severe burns, bile reflux, uremia, and enterovirus infections. It can be further categorized as hemorrhagic or non-hemorrhagic gastritis depending on whether bleeding occurs in the stomach lining.

Chronic gastritis develops gradually over months to years if left untreated. The primary cause is infection with Helicobacter pylori, a bacterium associated with peptic ulcer disease. Autoimmune disorders like Hashimoto's thyroiditis, age-related changes, and continuous bile reflux exposure also contribute to chronic gastritis development.

Reactive gastritis, also called gastropathy, results from prolonged exposure to medications like aspirin, alcohol, radiation therapy, or bile reflux, especially after gastric surgery. It causes histological mucosal lesions and mild inflammation. Though typically asymptomatic, reactive gastritis is detected through endoscopic examination.

Autoimmune metaplastic atrophic gastritis stems from an immune response against stomach parietal cells, leading to low chloride levels, intrinsic factor deficiency, and cobalamin malabsorption. This causes pernicious anemia and significantly increases stomach cancer risk, making early recognition and management essential for preventing serious complications.

Gastritis damages the stomach lining through reduced gastric mucus secretion, disruption of the mucosal barrier, or decreased blood flow to the mucosa. These mechanisms allow irritants and pathogens to injure the gastric mucosa. Management involves removing the irritant and supporting the stomach's natural healing process.