Anemia is also called low hemoglobin. It’s a decrease in healthy red blood cells. Red blood cells carry oxygen all over the body and deliver it to the individual cells that need it. Which cells need oxygen? All of them. Too few red blood cells means too little oxygen, which means cells sort of start to “starve” for oxygen. Anemia develops because red blood cells are lost (as in a severe bleed) because red blood cells are destroyed (by infection or certain illnesses or even treatments) or because the body isn’t producing them (due to dietary deficiencies or disease). With so many possible causes, anemia could develop over time and have relatively mild symptoms, or develop quite quickly, as it does with a (often) life-threatening hemoabdomen. Anemia can be diagnosed by a complete blood count (CBC) but the cause of the anemia might not be immediately understood.