Chronic gastritis is a long-term inflammation of the stomach lining. It can be caused by factors such as Helicobacter pylori infection, prolonged use of nonsteroidal anti-inflammatory drugs (NSAIDs), or excessive alcohol consumption. Symptoms may include stomach pain, nausea, and indigestion, but some people may not experience any noticeable symptoms. Diagnosis typically involves a medical history review, physical examination, and tests like endoscopy or biopsy. Treatment focuses on addressing the underlying cause, which may include antibiotics for H. pylori infection or medications to reduce stomach acid. Lifestyle changes, such as diet modification, can also help manage symptoms.