Feeling of heaviness in the stomach is often associated with a decrease in appetite, dull pain, nausea, in this case, a condition called gastric dyspepsia.
It is based on violations of gastric juice and a violation of peristalsis (contractions) of the stomach. This happens with gastritis, peptic ulcer and gastric tumors, as well as disorders of the liver, pancreas and intestines.
Heaviness in the abdomen, especially in the right upper quadrant, combined with a bitter taste in the mouth, nausea and headaches, points to the liver or biliary system. This condition is called biliary or hepatic dyspepsia. It is caused by disorders of the biliary tract, liver, gall bladder and duodenum. Both of these states - gastric and hepatic neuralgia is often a sign of serious disease of the gastrointestinal tract and are the reason to see a doctor, a gastroenterologist.