 Hey everybody, Dr. O, we've been talking about normal red blood cells or normal red blood cell amounts, but in this video we're going to talk about anemia. So anemias are when you don't have enough red blood cells or don't have enough functional red blood cells. So the first one you see here is sickle cell anemia, sometimes called sickle cell disease. This is a genetic condition where there's something wrong with the shape of hemoglobin, so you don't have normal shaped red blood cells. You have the sickle shaped red blood cells like you see here. So this can be a heterogeneous or homogenous condition depending on how many of these genes you get, these faulty genes you get, but calling them faulty is kind of tricky. If you only get one, then you have quite a few normal red blood cells and then you have some of these sickle cells. If you get two of them, then you're going to have a lot more of your red blood cells are going to have the sickle shape. So that's really not an ever a good thing, but it's kind of interesting if you wonder like why do people of Southeast Asian or African descent still carry the genes for sickle cell anemia? Why would it survive along with us as a species? Well, it actually what it does, if you have one copy of the sickle cell gene, you are less likely to develop cerebral malaria, less likely to die from malaria. So in some parts of the world, it's still advantageous to have one quote unquote bad copy of these genes. That's why calling a gene good or bad is it really always depends on the situation in the environment. So that would be sickle cell anemia as one type, other types of anemia you're going to see many of them are nutrient deficiencies. So the most common nutrient deficiency in the world is iron. So iron deficiency leads to what's called a microcytic anemia. We have too few red blood cells and the ones we have are tiny because there's not enough iron to actually produce the functioning hemoglobin we need. On the flip side, if you're deficient in folate or B12, you would have what's called a macrocytic anemia. Folate and B12 are both needed for proper cell division. So if you don't have enough folate or B12, you're going to see these large red blood cells. And the reason they're so big is they were supposed to be two. They're not properly dividing. Specifically, a B12 deficiency, you'll often hear that called pernicious anemia or else just folate deficiency anemia. Then you have aplastic anemia. What that means is you don't have enough of the stem cells in your bone marrow to produce enough red blood cells. So that can be genetic, but also it can be there's medications, chemotherapy, radiation, infections. There's lots of things that can lead to aplastic anemia. Then lastly, you have what's called the thalassemias. So thalassemia is a genetic inherited condition where red blood cell maturation doesn't occur like it should. So you won't have the normal number of healthy, fully functioning red blood cells. All right, that's just a real quick high level view of the different types of anemias. I hope this helps. Have a wonderful day. Be blessed.