Symptoms of gastric cancer include nausea, vomiting, acid reflux, pain in the upper abdomen, and a sense of fullness and discomfort, especially after eating, which are some of the early symptoms. As the tumor progresses, symptoms can worsen, including pain, vomiting of blood, and black stools indicating upper gastrointestinal bleeding. If the tumor is near the pylorus, it can cause pyloric obstruction, which manifests as acid reflux followed by vomiting of undigested food from the previous night. In the late stages of gastric cancer, patients may experience fatigue, weight loss, severe cachexia, and anemia. These are symptoms of advanced gastric cancer.