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8 Potential Warning Signs of Stomach Cancer

Nausea, heartburn and weight loss may signal more is going on with your GI system

man with stomach pain

Though we all get stomachaches from time to time, pain isn’t typically an early symptom of stomach cancer.


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So, what should you be on the lookout for instead?

General surgeon Daniel Joyce, MBBCh, shares what symptoms you might experience and when to see a doctor.

What is stomach cancer?

Stomach cancer, also known as gastric cancer, affects your stomach. Located in the upper portion of your abdomen (your gastrointestinal tract, or GI), your stomach digests the food you eat. Stomach cancer happens when there’s abnormal cell growth in your stomach.

Over the last 10 years, doctors have seen a decline in stomach cancer. According to the American Cancer Society, stomach cancer accounts for about 1.5% of all new cancers diagnosed in the United States each year.

The main reason for the decrease in cases is likely that infections from Helicobacter pylori, a type of bacteria known more commonly as H. pylori, are being diagnosed earlier than they used to be. H. pylori is believed to be one of the major causes of stomach cancer because it can cause chronic inflammation in your stomach lining, as well as ulcers.

“Now that we’re making the diagnosis of H. pylori earlier when patients get symptoms, they’re treated with antibiotics, the infection is eradicated and the overall risk of stomach cancer is decreased,” Dr. Joyce explains.

But Dr. Joyce warns that a particular type of stomach cancer called gastroesophageal junction adenocarcinoma is on the rise. This cancer starts in your esophagus, the tube that connects your mouth to your stomach.

“There’s a problem with obesity in the U.S.,” says Dr. Joyce. “That causes more acid reflux in the esophagus, which leads to a condition called Barrett’s esophagus, and that can ultimately lead to cancer.”

Early warning signs

Early stomach cancer symptoms are typically so unremarkable that they go completely unnoticed.

Stomach cancer is one of those tricky diagnoses. Most people may feel symptoms, but they’re usually vague. Those symptoms can be confused with many other benign (noncancerous) gastrointestinal (GI) disorders.

Because these symptoms tend to be dismissed as normal GI issues — and they are for most people — when stomach cancer is finally diagnosed, it’s often in the advanced stages.

But there are some early warning signs you can look out for:


Your stomach may feel full and tight, says Dr. Joyce.

“Stomach cancer can make the wall of your stomach very rigid and reduce its capacity to store food,” Dr. Joyce notes. “In cases where the stomach cancer spreads to the lining of the abdomen, it can cause an accumulation of fluid within your abdominal cavity.”

It can lead to excessive bloating to the point where you might look like you’re nine months pregnant.


Who hasn’t experienced heartburn, especially after a night of eating hot wings and pizza?

Heartburn, a burning pain in your upper chest and throat, is common, says Dr. Joyce, and isn’t usually something to be worried about.

But if you have prolonged heartburn that doesn’t go away with antacids or other medications, there may be cause for concern.

“If there’s a large cancer growth at the stomach’s exit point, fluid can accumulate and the path of least resistance can be back up the food pipe/esophagus,” says Dr. Joyce.

Nausea and vomiting

Another symptom of having a growth block the exit of your stomach? Feeling nauseated and even vomiting.

The foods you eat and the liquids you drink can’t make their way to your duodenum, which is the first part of your intestine.

“When you eat food, it has nowhere to go,” says Dr. Joyce. “That sends signals to your brain and you experience the sensation of nausea.”


A general feeling of discomfort

You may just have a feeling that something is off. This general feeling of discomfort may be due to stomach cancer spreading to the lining of your abdomen.

“It can feel like bloating,” says Dr. Joyce. “Your belly may feel heavy.”

Unexpected weight loss

If you’re experiencing other symptoms like nausea, vomiting and bloating, you may not eat as often to avoid feeling sick.

“People no longer feel hungry and ultimately start losing weight without trying,” says Dr. Joyce. “That’s probably the most concerning symptom.”


According to Dr. Joyce, this could be from a slow blood loss, which, coupled with unexpected weight loss, can be a sign of cancer.

Blood loss can also lead to anemia, a low red blood cell count, that’s likely the source of your exhaustion.

Blood in your stool or vomit

This symptom is much less common, but can happen if you’re losing a lot of blood. You may notice a change in your stool to a very dark stool, which is called melena.

“If it’s a very slow bleed, you may not notice anything in your stool,” says Dr. Joyce.

Feeling full

You feel full, even after you’ve only eaten a small amount. Known as “early satiety,” you’re unable to eat an entire meal without feeling full.

“You may only be able to eat 20% of what you would normally eat,” explains Dr. Joyce.

How to tell if your symptoms are serious

Most of the time, these symptoms are caused by something else, but it’s best to get them checked out, so if you do need treatment, you can get it as soon as possible.

If you experience nausea, bloating, weight loss and lack of appetite, Dr. Joyce recommends you see your doctor for testing.

Other factors can increase your risk of developing stomach cancer, too, like:

  • Smoking.
  • Helicobacter pylori (H. pylori) infection.
  • Age (your risk goes up as you get older).
  • Obesity.
  • A diet high in smoked foods, salted fish and cured meats.
  • A family history.

When to call your doctor

If your symptoms persist, don’t hesitate to see your doctor.

“Your doctor will do a comprehensive evaluation and ask about your family history to determine whether further investigation is required,” says Dr. Joyce.

If more testing is needed, there are a few options available:

  • An upper endoscopy. A thin tube with a tiny camera attached is inserted through your mouth and into your stomach. A biopsy, or sample of tissue, of any areas in question will be taken.
  • Endoscopic ultrasound. A thin tube with an ultrasound probe is placed in your stomach through your mouth. By getting a visual of your stomach, your doctor can help determine the stage of your cancer.
  • CT scan or MRI. If the tumor is large enough, these radiologic tests will detect it.


To treat stomach cancer, your doctor may recommend chemotherapy, immunotherapy and radiation. Surgery is an option, but your doctor may opt for other routes first. Some very early gastric cancers can be treated endoscopically (a thin tube with a camera on the end, and tiny instruments), too, but that’s a rare situation in the U.S.

“There’s significant potential for spread of cancer to other areas,” says Dr. Joyce. “So, we often recommend chemotherapy before proceeding with a surgery.”

Are there ways to lower your risk?

“As a society, we eat a lot of processed and unhealthy foods that cause these benign symptoms that we have. We really need to shift back to a cleaner, mostly plant-based diet,” advises Dr. Joyce. “There’s no doubt that the data supports a diet that’s rich in fresh vegetables, minimal fruit and minimal meat, especially processed meat. Avoiding these toxic foods will not only decrease a person’s risk for cancer development, but also the digestive symptoms from eating them.”

But don’t panic if your gastrointestinal system seems to be acting weird.

“Most of the time, GI symptoms are not from stomach cancer — they have benign causes,” assures Dr. Joyce. “Our gastrointestinal systems are quite fickle sometimes.”


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