Iron-deficiency anaemia. Light micrograph of a blood smear in a patient suffering from iron- deficiency anaemia. This is the most common form of anaemia worldwide. It is caused by a deficiency of iron, an essential component of the blood pigment haemoglobin. Here, a field of red blood cells (spherical structures) is seen. Due to this form of anaemia these cells stain poorly (they are hypochromic). Many of the cells are irregularly shaped and smaller than normal. This reduces their oxygen-carrying capacity. Symptoms include tired- ness, dizziness, and pale skin. A white blood cell (at centre, purple) serves to fight infection. Giemsa stain. Magnification: x630 at 35mm size.