 Welcome back. Today we're going to take a deeper look into the microcytic anemias. First and foremost, as we have discussed, microcytic anemias have a mean corpuscular volume, or MCV, that is less than 80 femtiliters. As a side note, a femtiliter is the same as a cubic micrometer. The first microcytic anemia we will discuss today is iron deficiency anemia. As you can see in this photo, to the right, the iron deficiency anemia has a red blood cell with central pallor due to the decrease in iron and in the decrease in the volume of the red blood cell. We will also discuss alpha thalassemias, beta thalassemias, lead poisoning, and citroblastic anemia, which are all microcytic anemias. So let's start with iron deficiency anemia. Iron deficiency anemia can be caused by two different types of problems. It can be to a decreased amount of iron in the body, which is often seen with four different types of ideologies. The first being chronic bleeding, chronic bleeding from the gut, from anywhere on the body. Chronic bleeding is different than acute bleeding. With acute bleeding, you will not see a decrease in the iron in the body. You have a total decrease in the volume of the blood, and it is a short term problem. When you have chronic bleeding over a long period of time, that's when you see issues with a decrease in iron in the body. You can also be due to malnutrition. Malnutrition is mitigated actually in the western world, often by fortifying flour with iron. So in our breads and other cooking products, we have iron in our diet that will help decrease the risk of an iron deficiency anemia. There are also some absorption disorders that can cause an iron deficiency anemia, namely irritable bowel disease, as well as celiac. A history of surgery specifically on the bowels, bowel resection can cause a decreased iron in an iron deficiency anemia. The second disorder that can cause an iron deficiency anemia is due to an increase in demand. This is often seen in pregnancy. In pregnancy, there is an increased demand for iron as the increase in blood volume in blood cells occurs. But if there is not an increase in iron in the diet or in vitamins, then there will be a decrease in the iron in each blood cell. So let's look and see what labs will show in an iron deficiency anemia. So the total body iron stores will obviously be down. It's an iron deficient anemia. The total iron binding capacity of the blood is going to be increased. You have less transferatin that is bound to iron. Therefore, there is more binding sites for iron increasing the TIBC. Ferritin is decreased. Your red cell distribution width is going to be increased because the body is producing more red blood cells at a faster rate and they're not maturing. And your reticulocyte index will be decreased. Moving on, the symptoms for iron deficiency anemia include fatigue, conjunctival pallor, that is the skin around the eyes, will be pale. Pica is a craving or a compulsive eating of certain foods or non-food items. We often discuss this with psychiatric disorders. Coiloneica, this is a spooning of the nails and the nail beds as you can see here with this gentleman. The nails have a spoon shape to them at the end there. And we also see glossitis. Glossitis is a bald or shiny appearance of the tongue that has a loss of color. Iron deficiency anemia is also seen along with a triad of symptoms in plumber-vinson syndrome. So in plumber-vinsins you get iron deficiency anemia, esophageal webs, and dysphagia. This is a very rare syndrome, but the USM only does love these type of questions because they are very specific. So be very aware of the plumber-vinsins syndrome triad.