Chronic gastritis manifests differently across various types, and the severity of symptoms may not always correlate with the extent of the lesion. There are roughly four types: 1. The first can cause upper abdominal pain or discomfort. Most patients with gastritis experience a sense of discomfort in the upper abdomen, with irregular pain that is not significantly related to diet; some may experience pain that spreads throughout the upper abdomen, causing a burning sensation, hidden pain, or bloating. 2. Post-meal fullness can also lead to abdominal distension due to the retention of food and poor digestion in the stomach. 3. Other symptoms include acid reflux and nausea. 4. Severe atrophic gastritis can cause weight loss in patients, including symptoms like diarrhea.