13 Signs and Symptoms of Stomach Cancer

Stomach cancer can start discreetly, making it crucial to pay attention to your body’s signals. Many people dismiss the initial symptoms as common digestive issues, which is why the disease frequently goes undiagnosed.

Stomach cancer develops when healthy cells in the stomach lining turn cancerous and multiply uncontrollably, leading to tumor formation over time. However, early detection significantly improves the chances of successful treatment and long-term survival.

Early Symptoms of Stomach Cancer

Many of these symptoms are common in other conditions, such as an ulcer or an infection, making stomach cancer challenging to detect.

Regular screening for persistent symptoms can help identify the disease at an early stage when treatment is most effective and outcomes are improved.

Persistent Indigestion

If you experience indigestion lasting more than two weeks, it may be a sign of an underlying issue related to stomach acid. Indigestion from stomach cancer may occur daily or become progressively more frequent, often worsening after meals.

You might feel persistent discomfort, pressure, or a dull, aching pain in your upper abdomen that does not fully resolve with dietary changes or over-the-counter medications.

Symptoms can fluctuate, especially after large, fatty meals, as the stomach is forced to work hard, with some days feeling normal and others bringing significant discomfort.

Easily Feeling Full

Feeling full too soon happens when you become satisfied after consuming only a small portion of food. Even after a few bites, your stomach may feel tight, pressured, or overly full, often accompanied by bloating, mild nausea, or excessive burping.

Over time, you may unconsciously eat less, which may lead to unintentional weight loss. This can happen due to the tumor pressing against the stomach walls and reducing its capacity, or delayed gastric emptying, which slows digestion of ingested food.

Heartburn

Heartburn is a painful burning sensation behind your breastbone that may also reach your throat, causing a sour or bitter taste in your mouth.

A stomach growth may add resistance to the natural downward movement of digested food and cause digestive juices to flow back up to the esophagus as the stomach fills.

It tends to worsen when lying down, bending over, or consuming specific foods, including spicy dishes or high-fat meals.

Occasional heartburn is common and usually improves with lifestyle changes or over-the-counter medications. However, a medical evaluation is recommended if heartburn becomes more frequent, intense, or suddenly starts after age 50.

Loss of Appetite

Loss of appetite can develop gradually and persist for weeks. You may notice that food seems less appealing and that you feel less hungry than usual, even after long periods without eating.

Meals that once tasted enjoyable might now seem bland or unappealing. As a result, you may start eating smaller portions without realizing it or begin skipping meals entirely to avoid discomfort.

In some cases, loss of appetite may be caused by the body’s inflammatory response to cancer. This response can alter metabolism, suppress hunger signals, and contribute to unintentional weight loss.

Mild Stomach Discomfort or Pain

You may experience occasional stomach discomfort that comes and goes without a clear pattern. The sensation is related to indigestion, often dull, achy, or pressing rather than sharp.

The pain usually stays in one area but can sometimes spread to your lower abdomen or back. Some people also report mild bloating, pressure, or nausea alongside the discomfort.

Mild Nausea

You may experience mild, unsettled nausea throughout the day. This nausea may not have a clear trigger, but could feel worse after eating normal meals, particularly rich or fatty foods.

Some people also experience mild nausea or discomfort not related to food digestion, and it happens even when they are just thinking about food in anticipation of the discomfort.

Some people notice a lingering queasiness in the morning that lasts beyond breakfast. The nausea is typically not severe enough to cause vomiting, but may persist for weeks.

Advanced Symptoms of Stomach Cancer

People often don’t realize anything is wrong until the cancer has progressed to an advanced stage. At this point, the tumor has grown significantly or spread beyond the stomach (a process called metastasis), leading to more severe symptoms.

Stomach cancer at this stage is often life-threatening, as treatment becomes more difficult, involving the cancer cells invading other organs. While treatment can control symptoms and slow progression, the primary focus is improving quality of life rather than a cure.

Unexplained Weight Loss

You may experience noticeable and unexplained weight loss without any changes to your diet, physical activity, or daily routine. This can happen gradually over weeks or months, with some people losing around 10 pounds or more in a short period of time.

Stomach cancer can interfere with your body’s ability to absorb nutrients, making it harder to maintain weight even if you continue eating normally.

In some cases, cancer increases metabolism, causing the body to burn energy faster than usual, leading to cachexia (cancer-related muscle loss).

Fatigue & Weakness

You may feel persistently tired, even after a full night’s rest, and find that simple tasks leave you exhausted. Fatigue may start mildly but can worsen over time, making it harder to stay active.

You might need frequent breaks, struggle with daily activities, or notice that standing, walking, or lifting objects for long periods becomes difficult. Muscle weakness may develop, making movements feel more laborious than usual.

Some people also feel dizzy or lightheaded, especially when standing up too quickly. Poor nutrition due to reduced appetite, difficulty swallowing, or reduced nutrient absorption can deprive your body of the energy it needs.

Severe Abdominal Pain

You may experience persistent or worsening abdominal pain that can range from dull, aching discomfort to sharp, stabbing sensations. The pain often begins in your upper abdomen but can spread to the lower belly, sides, or back as the cancer grows.

Pain may worsen after eating, particularly large or heavy meals. Some individuals feel burning pain if the tumor damages the surrounding tissues, while others experience cramping pain if there is a blockage preventing food from passing.

Vomiting

As stomach cancer progresses, vomiting may become more frequent, occurring shortly after eating or even when your stomach is empty. If a tumor obstructs the stomach passage, vomiting may be forceful or projectile.

The presence of blood in vomit is a critical warning sign that should not be ignored. Blood can appear bright red, signaling active bleeding, or dark and grainy, resembling coffee grounds, which indicates the presence of older, partially digested blood interacting with gastric juices.

Difficulty Swallowing

Difficulty swallowing, known as dysphagia, can develop as stomach cancer advances. It often starts with solid foods but may gradually worsen, eventually making it difficult to swallow even liquids.

You might experience a tight or pressured sensation in your throat, making eating and drinking more challenging. In severe cases, swallowing may become painful, and you may unintentionally choke or cough while eating, especially with liquids.

This difficulty occurs when a tumor narrows the passage to the stomach, cancer spreads to the esophagus, or damage to the nerves controlling swallowing prevents food from moving smoothly.

As the condition worsens, there is an increased risk of aspiration, where food or liquid enters the airway instead of the stomach, which can lead to serious complications.

Changes in Stool Color

Melena is a serious warning sign of stomach cancer and occurs when a tumor in the stomach causes internal bleeding. As blood passes through the digestive tract, it is partially digested, resulting in dark, sticky, and foul-smelling stools.

Initially, the color change may be subtle, but stools can become progressively darker and more tar-like as bleeding continues. This often indicates bleeding from a stomach tumor damaging blood vessels or causing ulcers.

Stomach Swelling

As stomach cancer advances, fluid may build up in the abdomen, causing it to swell or feel tight, even if your weight remains the same.

You may notice that your clothes feel tighter around your waist, and you might experience bloating, nausea, or abdominal pain.

As fluid accumulates, the increased pressure in the abdomen can push against the diaphragm, making it harder to breathe comfortably, especially when lying down.

This condition occurs when cancer blocks normal fluid drainage or affects liver function, leading to excess fluid retention. As a result, patients may experience swelling extending to the limbs, which can cause discomfort and complicate their overall health.