Medessence on Instagram: "Upper gastrointestinal (GI) bleeding is serious bleeding from the esophagus, stomach, or duodenum (first part of the small intestine) and appears as vomiting blood (hematemesis) or black, tarry stools (melena). Common causes include peptic ulcers, gastritis, Mallory-Weiss tears (from retching), varices (swollen veins, often from liver disease), and NSAID use, requiring immediate medical attention, often with endoscopy for diagnosis and treatment like fluid replacement.