Anaemia is the condition when a person's body has fewer amount of red blood cells. If a person suffers from iron deficiency, less haemogobin will be made and this will result in fewer red blood cells.
Mild anemia corresponds to a level of hemoglobin concentration of 10.0-10.9 g/dl for pregnant women and children under age 5 and 10.0-11.9 g/dl for nonpregnant women. For all of the tested groups, moderate anemia corresponds to a level of 7.0-9.9 g/dl, while severe anemia corresponds to a level less than 7.0 g/dl.
If left untreated, iron-deficiency anemia can cause serious health problems. Having too little oxygen in the body can damage organs. With anemia, the heart must work harder to make up for the lack of red blood cells or hemoglobin. This extra work can harm the heart.