1 Red blood cells (RBCs) are also called erythrocytes. They make up almost half of blood. Red blood cells are filled with hemoglobin. That's a protein that picks up oxygen in the lungs and brings it to cells all around the body.  White blood cells (WBCs) are also called leukocytes.
Pain originating in the stomach or esophagus is often felt in the upper abdomen and can be due to heartburn, gastroesophageal reflux disease (GERD), or hiatal hernia (weakening in the diaphragm that allows the stomach to protrude into the chest). You may also have gastritis (inflammation of the stomach lining) or ulcers.
What can cause upper stomach pain, indigestion, and gas accompanied by a dull aching pain in my back? I have had the gas and indigeston for a couple weeks now and the back pain just recently started. Related Topics: Indigestion, Stomach, Pain, Back Pain.