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Current time:0:00Total duration:12:36

Video transcript

iron deficiency anemia is anemia due to a deficiency in iron and this is a type of micro - type of micro CITIC anemia but that's something you already know because of this diagram in which you saw that iron is really important component of heme and heme is essentially half of hemoglobin right so that if you don't have iron you certainly can't make him and without him you can't make hemoglobin and anytime you have a problem with making hemoglobin you end up with a microcytic anemia and a microcytic anemia refers to an anemia where you end up with really small red blood cells so why does that happen is that just something that happens by accident well no it's something that the body does intentionally so in any condition where you have a problem with making hemoglobin such as with iron deficiency anemia you end up with these red blood cells that have fewer hemoglobin molecules than they should right so you see something like this where you have this big old cell with very little filling on the inside and the body responds to this by cutting this red blood cell in half so that you end up with smaller red blood cells like this and each has a small amount of hemoglobin on the inside but the point is that the concentration of hemoglobin inside each of these really small cells is essentially very close to what you'd see in a normal cell it's almost like if you had a jelly doughnut that had very little jelly on the inside and so the donut shop tried to make up for that by shrinking the donuts down into munchkins so that you had these really little munchkins that were filled plump with jelly on the inside okay so if you already know all that about iron deficiency anemia what's there left to learn well one of the things we haven't talked about is the causes of iron deficiency anemia so we'll talk a little bit about the causes of iron deficiency anemia and I like to think of the different causes is belonging to one of four different groups and as you can probably tell I like to think of things in terms of because it helps organize my thinking so that I do very little memorization and more rationalization alright so when you usually think of iron deficiency you're you're probably most likely to think of a person who isn't taking in enough iron through their diet so you're probably most likely to think of a cause of decreased intake decreased dietary intake and we get iron through the diet in foods like green leafy vegetables and meat so certainly somebody who isn't taking enough quantities of these types of foods will have iron deficiency but really decrease intake is most problematic in little infants little infant especially those infants less than six months old and that's because when you're younger than six months old your diet consists almost entirely of breast milk and breast milk is a really poor source of iron and that's why these infants end up with iron deficiency and then iron deficiency anemia alright so another cause of iron deficiency is an increase in the body's demand increasing the body's demand of iron and really you'll see this in one of two types of patients the first type of patient is either a child or an adolescent adolescent the second type of patient you'll see this in is a pregnant woman pregnant the pregnant woman okay so you know that during childhood and adolescence we undergo a really rapid rate of growth and along with that rapid rate of growth we experience a rapid expansion in our blood volume so our blood volume has selca it has to increase as well so in order to increase the blood volume the number of red blood cells has to increase and you can't increase the number of red blood cells if you don't increase hemoglobin production and that increase in hemoglobin production requires increased iron and so that's what account for the increase in the body's demand of iron during childhood and adolescence and you see something very similar going on in pregnant women so during pregnancy you can see up to a 20% increase in your in your blood volume to accommodate the needs of the growing fetus inside the woman and so that accounts for the increase in the demand the body's demand of iron so it's very easy for these two types of patients to not take in enough iron through the diet to meet the increase in the body's demand and that's how they end up with iron deficiency so let's say you have a patient then who's taking in enough iron through the diet but for some reason or another that iron isn't making its way through the gut and into the body so what I mean to say is let's say there's a problem or a decrease in the absorption in the absorption of iron and to understand the different situations that could lead to a decrease in the absorption of iron we'd have to talk about how the absorption of iron normally occurs so here's so here's a man okay the reason why I put him in here is to show you that when you take an iron through the diet goes in through the mouth through the esophagus through the stomach and then to this point this point right here called the duodenum the doís then okay and so the duodenum is a point where you really absorb almost all of your nutrients including iron but before iron makes its way through the duodenum and it's absorbed in the duodenum it has to go through the stomach and it's really important for the iron to pass through and encounter the stomach because the stomach contains lot of acid so that's what I'm drawing in green over here contains lots of stomach contains lots of stomach acid and the stomach acid is essential for converting the iron that you take in through your diet into a form that's more easily absorbs through the duodenum it's really important for serving that function so going back to this diagram that we're making over here there are really two ways that you could end up with a problem in the absorption of iron the first way is you could just not be making enough stomach acid so you have a decrease in the production of stomach acid the second cause the second way you could end up with a problem in the absorption of iron is having some sort of some sort of some sort of problem in the duodenum in the duodenum in the duodenum so first let's talk about this decrease acid production this really happens very commonly in two types of patients the first is the patient who's taking a drug called a proton pump inhibitor I've abbreviated that PPI so proton pump inhibitor so that's a type of medicine that you take for the treatment of esophageal reflux disease acid reflux disease so that's that's a disease in which you have acid refluxing or going backwards from the stomach into the esophagus and it causes irritation of the esophagus most commonly referred to as heartburn so in order to relieve the symptom of the heartburn patients will take a drug called a proton pump inhibitor that decreases the production of this stomach acid now with decreasing the production of the stomach acid you get a relief in the symptom but along with that you get a reduction in the absorption of iron through the duodenum okay so that's a one way in which you could end up with a problem in the absorption of iron a second type of patient in which you'll see a decrease in the production of stomach acid is a patient who has had a gas Trek to me I guess directa me and a gastrectomy refers to either the partial or the entire removal of the stomach well why would somebody have either part of their stomach or their entire stomach removed well there could be a couple of different reasons why this would occur but first is it could be done for weight-loss reasons to aid in weight loss the second reason is it could be done to remove a stomach cancer or even perhaps a stomach ulcer but for whatever reason the point that we're focusing on over here is with the removal of part of the stomach you have a decrease in the production of stomach acid which decreases the conversion of iron into the form that's more easily absorbed by the duodenum leading to iron deficiency and then leading to iron deficiency anemia all right so that's the first cause of an impaired absorption of iron the second cause a is with some dysfunction in the duodenum or some problem in the duodenum and really you see this in patients who have celiac celiac disease and celiac disease refers to patients who have an intolerance of gluten so gluten is something that's found in different foods in your diets found in in wheat barley rye and other types of similar food and when patients with celiac disease encounter these encounter gluten in their diet it leads to an inflammation and a destruction of the cells in the duodenum so that the duodenum doesn't do as good of a job of absorbing nutrients including iron and so that's how patients with celiac disease end up with iron absorb malabsorption or a decreased absorption so finally we have to consider what I think is the most important cause of iron deficiency anemia so let's say you have a patient who's taking in enough iron through their diet and all of that iron is making its way into the body but for some reason or another they have an increase in the loss of iron from the body and usually usually you see this with blood loss okay because with blood loss you lose the red blood cells and then with that comes a loss of the hemoglobin inside the red blood cells and with that comes a loss of the iron that's inside the hemoglobin right so that's how you end up with iron deficiency and you see this in a few few different cases the first especially encountered or really only encountered in young women who have not yet encountered menopause is heavy is heavy menstrual bleeding or heavy menstruation menstruation another cause is peptic ulcer disease which I've abbreviated PUD and peptic ulcer disease refers to when you have ulcers either in the duodenum or sometimes in the stomach and a lot of times these ulcers can bleed and with that increase in blood loss you can end up with iron deficiency right one of the most important causes of increased blood loss leading time is colon is colon cancer okay most often encountered in elderly patients and colon polyps and the reason why this is so important aside from the increase in mortality that you see with this condition is because a lot of times this goes unnoticed to the patient so the patient doesn't notice that there's blood being lost through the GI tract in their stool it's usually only when an elderly patient presents with iron deficiency anemia and you workup that iron deficiency anemia and try to figure out what the cause of it is that you discover that he or she has an underlying colon cancer so it's something to always keep in the back of your mind especially when an older person presents with colon cancer all right so then let's finally discuss one of the most common causes of blood loss in developing countries and that is a hookworm hookworm infection and these hook worms can can inhabit your intestines and literally latch themselves on to the wall of your intestine and suck out blood leading to blood loss so these are the different causes lots of the most commonly encountered causes of iron deficiency anemia keep in mind that iron deficiency leads to a problem with making hemoglobin which then ultimately leads to a microcytic anemia