Signs and Symptoms of Stomach Cancer

The signs and symptoms of stomach cancer, also known as gastric cancer, range from blood in the stool to abdominal pain. Oftentimes, however, stomach cancer does not have symptoms, particularly in the early stages, or the symptoms may be non-specific and easily mistaken for other conditions.

Symptoms alone cannot diagnose stomach cancer. Only an investigation by a healthcare provider, which may involve imaging studies and a biopsy, can definitively diagnose the disease.

Symptoms of stomach cancer can vary based on the stage of the disease as well as the type of cancer you have, some of which may be more aggressive than others.

Although the signs can often be vague, there are seven symptoms commonly experienced in people with stomach cancer.

Blood in the Stool

Blood in the stool can be a symptom of stomach cancer but can occur with other noncancerous conditions as well. The color of blood in the stool often provides important clues as to the origin of bleeding.

This may mean that there is cancer in the colon or rectum (colorectal cancer) or that a noncancerous condition like hemorrhoids, anal fissures, or ulcerative colitis are involved.

By contrast, stools that are black and tarry are signs that bleeding is occurring in the upper portion of the gastrointestinal tract. This is because the blood will progressively darken as it makes its way to the rectum.

Black and tarry stools, referred to as melena, occurs when hemoglobin with blood reacts to digestive enzymes and intestinal bacteria. The most common causes of melena are peptic ulcer disease, liver disease, and gastric cancer.

Blood in the stool is not always visible to the eye. Your stool can contain trace amounts of blood that only a test, such as the fecal occult blood test (FOBT), can reveal.

Abdominal Pain

Abdominal pain is one of the most common signs of stomach cancer and the symptom that usually prompts people to seek medical attention. Symptoms can range from persistent mild discomfort to severe pain. The pain and discomfort generally occur in the upper abdomen area.

With that said, due to the way the nerve signals are delivered to the brain, the location of the pain doesn't necessarily reflect the source of the pain. Stomach pain can sometimes occur due to problems with the liver, esophagus, pancreas, and other regional organs.

Abdominal pain has many possible causes that are far more common than stomach cancer. These include stomach flu, gastritis, pancreatitis, and gastroesophageal reflux disease (GERD), among others.

Other types of cancers that involve abdominal pain include pancreatic cancer, liver cancer, bile duct cancer, and gallbladder cancer.

Persistent Nausea or Vomiting

Nausea and vomiting are also common symptoms of stomach cancer. While there are a plethora of other conditions that cause nausea or vomiting, the persistence of symptoms is generally a sign of a more serious medical condition.

If symptoms are persistent or you vomit up blood—even if just a small amount—make an appointment to see your healthcare provider right away. Bloody vomit, also known as hematemesis, may be a sign of cancer or a noncancerous condition like a peptic ulcer, severe GERD, or esophageal varices.

Bleeding from the stomach can also give vomit a coffee ground-like appearance. This is more typically seen when stomach cancer is advanced but can also be the result of conditions affecting the esophagus or other parts of the upper gastrointestinal tract.

Changes in Bowel Habits

Changes in bowel habits, including diarrhea and constipation, are common occurrences that everyone experiences at one time or another. But persistent changes, including intermittent bouts of constipation and diarrhea, may be early signs of stomach cancer.

Cancer itself can alter digestion and lead to these problems. At the same time, as the malignancy spreads, it can cause the narrowing of the intestinal passageway (strictures) and the onset of constipation. The accumulation of fluid behind the stricture can eventually cause the release of watery diarrhea, typically accompanied by acute abdominal pain.

Loss of Appetite

It's not uncommon to lose your appetite for a day or two, but if you find that you just don't feel like eating for more than a few days, see your healthcare provider. Although stomach cancer is one of many conditions that can cause a loss of appetite, the persistent loss of appetite should raise concerns irrespective of whether cancer is involved.

People with stomach cancer may also experience early satiation, in which you feel full after eating only eating a few bites.

Cancer can change the body's metabolism and increase the production of inflammatory cytokines. These changes can affect the chemical messengers, called neurotransmitters, that influence appetite. If the tumor grows, it can also reduce the functional size of the stomach, promoting early satiation.

The persistence of these symptoms can lead to extreme weight loss, a condition referred to as cachexia. This is common in people with advanced cancer.

Bloating and Heartburn

Abdominal bloating can be a symptom of stomach cancer, especially when it occurs after meals. Even so, bloating is frequently missed in people with stomach cancer and ascribed to other, more common causes, such as indigestion, constipation, or menstruation.

Similarly, heartburn is more often related to conditions like acid reflux and GERD but can also be a sign of stomach cancer. The bacteria H. pylori is not only linked to GERD and peptic ulcers but significantly increases the risk of stomach cancer.

On the flip side, chronic acid reflux can lead to a condition called Barrett's esophagitis which, in turn, increases the risk of esophageal cancer.

Persistent Fatigue

Fatigue that lasts more than a few days or weeks may be suggestive of a medical concern. With stomach cancer, fatigue is often related to anemia due to blood loss in the stool.

At the same time, being under the burden of chronic inflammation can trigger fatigue—a phenomenon common in people with cancer, autoimmune diseases, and neurodegenerative disorders like Huntington's and Parkinson's disease.

Cancer-related fatigue is different than fatigue associated with exhaustion, depression, or acute illness. It is the kind of fatigue that doesn't improve with a good night's rest or other common interventions.

A Word From Verywell

It's not uncommon for people diagnosed with cancer to admit that they knew something was amiss. You simply may not have been feeling well or have a gut sense that something is wrong. Trust your intuition.

The worst thing that can happen is that you lose the time and money seeing a healthcare provider. Not listening to your inner voice could have far worse consequences.

If you are experiencing any symptoms of stomach cancer, see your healthcare provider promptly. An early diagnosis almost invariably leads to better treatment outcomes.