There are several causes of stomach cancer including smoking, unhealthy food and heredity. This may cause deformity in the DNA of cells that triggers rapid growth, division of cells and stomach cancer. 
Symptoms of Stomach Cancer
Mentioned below are some symptoms for stomach cancer.
Different Stomach Problems
Most common stomach cancer symptoms are problems related to stomach for several years like acidity, burping and indigestion. But it does not mean, all the people with these stomach problems develop cancer. Very few patients going to the doctor having these problems develop cancer. Some people also start having dark stool and bloody stool.
Weight Loss
Losing weight is one of the main signs. You will start losing weight gradually, more than 10% of your normal body weight without doing any fitness exercise or changing your food habits. Weight loss is caused by the growing cancerous cells that compress your intestines, and suppress your appetite.
Fluid in Abdomen
Sometime you may also have a lump in your stomach because of stomach cancer. A number of people also experience fluid getting collected in the abdomen which is known as Ascites.
Bleeding and breathlessness
Patients developing stomach cancers bleed internall which appears while vomiting. Too much loss of blood may result in less red blood cell count which results in Anemia. Once you get anemia, you may also feel breathlessness and start vomiting blood which is not an early symptom of blood cancer. The blood you vomit may be fresh which is red in color or brownish which means the blood has been stuck inside your body for a while.
Blood clots
Blood clots is common among those who have stomach cancer. Swollen legs or sudden chest pain along with blood clot in lungs or legs can be seen. To cure this, you you need to take in anti-clotting medicines recommended by doctors.
The sooner you identify the symptoms of the stomach cancer, it is easier to cure and more possibly the treatment turns successful. So, go for the treatment to the doctor as soon as you feel you may possess these symptoms.