Pain

• A burning pain in the abdomen is the most common sign of a stomach ulcer. The pain occurs because the ulcer is irritated by the acid produced in the stomach. Where the pain is felt will depend on where in the stomach the ulcer is located, but it is generally felt between the navel and the breastbone. In many cases, the pain will be worse at night, or when the stomach is empty.
  
  

Nausea

• In some cases, people with peptic ulcers will experience bouts of nausea as a sign of the condition. Some people may also experience vomiting along with nausea. Vomiting blood is also a sign of an ulcer, but it can also be a sign of a more serious condition. If you vomit blood, report it to your doctor immediately.
  
  

Black Stools

• Some people who have ulcers will notice that their stool suddenly appears black or tarry. This appearance is due to blood in the stool caused by the ulcer.
  
  

Changes in Appetite

• People with an ulcer may notice that their appetite has changed and they are less hungry than usual. Appetite changes are often subtle, and they sometimes occur in people with ulcers because the sores in the stomach can affect the desire for food.
  
  

Weight Loss

• Sudden and unexplained weight loss is also a sign of a stomach ulcer and often occurs in people who have noticed a decrease in appetite. Unexplained weight loss is a common symptom of medical problems, including serious conditions, and should always be reported to a doctor.