What are the early symptoms of gastric cancer?

Gastric cancer is the most common malignant tumor in China. Like other malignancies, it is easily mistaken for other localized conditions. Therefore, it is essential to understand the symptoms of gastric cancer—particularly those appearing in its early stages—so that it can be promptly detected and appropriately managed as soon as they arise, thereby seizing the optimal window for early intervention and treatment. Below, we address the question: What are the early symptoms of gastric cancer?

What Are the Early Symptoms of Gastric Cancer?

1. Upper abdominal pain

Many patients are not diagnosed with gastric cancer until the disease has progressed to an advanced stage—largely because they mistake its early symptoms for those of common benign gastric disorders. In the early phase, most gastric cancer patients experience gastric distension and discomfort or pain in the upper abdomen. Many assume this is simply a flare-up of gastritis and fail to recognize the warning signs. Such misinterpretation is highly dangerous and may significantly delay early detection.

2. Loss of appetite

For instance, during hot summer months, many people naturally experience reduced appetite. However, if decreased appetite occurs without seasonal or environmental triggers—and is accompanied by unexplained, progressive weight loss lasting for an extended period—you should take this seriously. These symptoms may indicate gastric cancer, and prompt medical evaluation—including endoscopic examination—is strongly advised to facilitate early diagnosis and timely treatment.

3. Nausea and vomiting

Some patients with early-stage gastric cancer experience persistent nausea and vomiting. If these symptoms last for a prolonged duration and are accompanied by hematochezia (blood in stool), immediate medical attention is warranted. Gastroscopy is recommended to confirm the diagnosis; if early gastric cancer is identified, surgical resection of the tumor may be performed to prevent further cancer spread.

4. Hematochezia (blood in stool)

Hematochezia has numerous potential causes, one of which is gastric cancer. Black, tarry stools—clinically termed “melena”—should raise immediate concern and warrant prompt medical evaluation to rule out gastric cancer. Similar symptoms may also occur in colorectal cancer; therefore, screening for colorectal malignancy is advisable as part of a comprehensive diagnostic workup. Regardless of the underlying cause, hematochezia is always abnormal and must never be ignored.

5. Anemia

Many people are unaware that anemia can be an early sign of gastric cancer. It arises when tumor cells invade and damage gastric blood vessels, leading to chronic gastrointestinal bleeding—manifesting as hematemesis (vomiting blood) or melena—and consequent iron-deficiency anemia. Common symptoms of anemia include pallor, dizziness, vertigo, insomnia, and fatigue. When anemia co-occurs with any of the above symptoms, gastric cancer should be considered, and targeted diagnostic testing—including upper endoscopy and biopsy—should be pursued.

The above outlines the key early symptoms of gastric cancer. We hope this information proves helpful to you.