Stomach cancer vs acid reflux: How to tell the difference

If you've ever had indigestion or burning pain in your chest or belly, you might wonder if it’s just common acid reflux or something more serious like stomach cancer. While some symptoms can overlap, it’s important to understand the differences so you can take action when needed. Here’s a breakdown to help tell these two conditions apart.

Acid reflux happens when stomach acid flows back up into the esophagus (the pipe connecting your throat to your stomach), causing a burning feeling known as heartburn. This condition is also called GERD (Gastroesophageal Reflux Disease) when it happens regularly or severely.

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Heartburn: A burning sensation in the chest, often after eating

Regurgitation: Sour or bitter taste from acid coming back up
Bloating or burping
Hoarseness or sore throat in the morning
Cough or a feeling of something stuck in the throat
Acid reflux is fairly common and usually can be managed with lifestyle changes and over-the-counter meds. But if it’s persistent or severe, it can cause damage and increase risks for other problems like Barrett’s esophagus and esophageal cancer .

Stomach cancer (also called gastric cancer) is when malignant cells grow inside the lining of the stomach. Unlike acid reflux, stomach cancer is much more serious but usually doesn’t show clear symptoms early on.

Loss of appetite or feeling full after eating a small amount
Unexplained weight loss
Belly pain or discomfort, often above the navel
Persistent heartburn or indigestion that doesn’t get better
Nausea or vomiting, sometimes with blood
Swelling or fluid buildup in the abdomen
Dark or bloody stools
Feeling very weak or tired, possibly from anemia

Many of these symptoms can be caused by other less serious issues, but if they linger or worsen, seeing a doctor is crucial.

Since some symptoms overlap, like heartburn and belly pain, it can be tricky to tell at first glance. Here are some tips:

Duration & persistence: Acid reflux symptoms often come and go, triggered by certain foods or lifestyle habits. Stomach cancer symptoms usually don’t improve and may get steadily worse.
Weight loss: Unintended weight loss is common in stomach cancer but rare in acid reflux.
Fullness & appetite: Feeling full quickly or loss of appetite points more toward stomach cancer.
Bleeding: Vomiting blood or black stools indicate bleeding in the stomach, which should be checked immediately.
Response to treatment: Acid reflux may improve with antacids or other medications. Persistent symptoms despite treatment raise suspicion for cancer or other serious conditions.

For acid reflux: Obesity, smoking, certain foods and drinks, hiatal hernia, pregnancy

For stomach cancer: Infection with Helicobacter pylori bacteria (a major cause), smoking, family history, certain diets low in fruits/vegetables, older age, and conditions causing chronic stomach inflammation

If heartburn is occasional and manageable, it’s usually not urgent. But if symptoms are persistent beyond a few weeks, worsen, or include the warning signs mentioned above (weight loss, vomiting blood, swallowing difficulty), get medical advice promptly.

A doctor may recommend tests ranging from bloodwork to endoscopy (using a camera to view the esophagus and stomach) to rule out cancer or other serious diseases.

Source: Harvard, US CDC, American Cancer Society