To be anemic means that there aren't enough red blood cells
flowing throughout your body. Red blood cells carry oxygen
throughout your body, so if you're anemic, everything from your
brain, to your heart, to your muscles aren't getting enough
oxygen to run properly. Iron is a key part of red blood cells.
When your body doesn't have enough iron, it'll make fewer red
blood cells or make cells that are just too small. If you lose
enough iron, you'll wind up with iron deficiency anemia - the
most common form of anemia. So, what causes iron deficiency
anemia? There are basically three main ways you can become iron
deficient. First, bleeding can cause you to lose more blood
cells and iron than your body can replace. Bleeding due to
ulcers, cancers, taking aspirin or other medicines can cause
anemia. In women, this can happen because of heavy or frequent
menstrual periods. The second way, your body isn't properly
absorbing iron, perhaps, due to an intestinal disease. Some
surgeries, like gastric bypass, can lead to