Stomach cancer often begins with unusual and persistent upper abdominal pain.

This pain is “sharp, frequent… and occurs both on an empty stomach and after meals,” without relief from painkillers.

Another early sign is a loss of appetite. Patients “feel uninterested in food… and may even fear eating.” Nausea may appear early but is often ignored because it’s mild at first. As the tumor grows, nausea worsens and may be accompanied by vomiting, bloating, and acid reflux.

Additionally, the cancer disrupts digestion, causing repeated “abnormal constipation or diarrhea.” These changes are persistent and not easily explained by diet or mild illness.