Iron deficency anemia diagnosis | Hematologic System Diseases | NCLEX-RN | Khan Academy
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Iron deficency anemia diagnosis | Hematologic System Diseases | NCLEX-RN | Khan Academy


– So the first step to
making a diagnosis of iron deficiency anemia is
taking a look at the patient. Seeing what signs and symptoms
they’re complaining of. So iron has a couple of
different roles in the body. So let’s talk about some of
the roles of iron in the body. So firstly, there’s one
role that we already talked a little bit
about, and that is that iron is responsible for making hemoglobin. So it makes hemoglobin. And because of that, when a
person is deficient in iron, they have troubles making hemoglobin, and that leads to anemia. And so the patient will
present with signs and symptoms typical of anemia, such
as fatigue, weakness, looking pale, feeling
short of breath, right? Now iron serves lots of
different roles in the body because it serves as a
cofactor for lots of different proteins and enzymes in the body. So the other role of iron I’m gonna very descriptively write down is other, OK? Because it serves too many
roles to list out individually. So for example, iron is really important for the health of skin, hair and nails. So when a person becomes
deficient in iron, they can have this thing
called koilonychia, which refers to spoon-shaped
nails, and I can’t draw it out. But if you were to look up the picture, you’d see that quite literally the nails are in the shape of a spoon. Also people who have iron
deficiency can experience pica, which is a desire to eat inedible things, such as dirt or ice. And iron deficiency can also
lead to restless leg syndrome. And we don’t know exactly know
exactly how iron deficiency leads to restless leg
syndrome, but we do know that there’s a very strong
association between the two. And again, this is all because
iron serves as a cofactor for lots and lots and
lots of different enzymes throughout the body. So somebody who is deficient
in iron presents not only with anemia, but also with
all of these other symptoms. So the first step, if a
patient comes in and has signs and symptoms of
anemia, and maybe a couple of these other symptoms,
maybe you’d start to think that perhaps there’s an
underlying iron deficiency anemia. So the first thing you
would do is draw some blood and check how many red
blood cells they have. And if they do have a true
decrease in the number of red blood cells, then
you’d say that definitively they do have anemia. But that tells you nothing about the cause of the iron deficiency anemia. So to establish iron deficiency
as a cause of anemia, you’d have to do something
called iron studies. But if we can ever hope to
understand anything at all about iron studies, first we
have to learn a little bit about the physiology of iron in the body. So here is a diagram, and the
reason why I put this in here is to show that when we
consume iron through the diet, it goes in through the
esophagus, through the stomach, and then it stops right
here, the first portion of the small intestine
called the duodenum. The duodenum. And the iron is absorbed at the duodenum. So expanding that a little
bit, here are the cells that line the duodenum,
and when iron presents in front of there, it gets
absorbed through these cells and into the bloodstream. But the iron doesn’t float
around in the bloodstream, willy nilly on its own. Instead, it’s bound to this
protein called transferrin. So transferrin transports the
iron through the bloodstream. And it transports it
through the bloodstream, and it takes it to distant
sites where it’s needed. But most of the iron is actually
transported to the liver because the major site of iron storage in the body is the liver. The iron is brought into the liver, and it’s stored in these
cells called macrophages. So here the iron is being
brought into the macrophage, and again, the iron isn’t just left alone and unbound in the macrophages. Instead it’s bound to
this really large protein called ferritin. And you might be asking
yourself, well, why is the iron, whether it’s in the
bloodstream or whether it’s inside a cell, why is it
always being chaperoned by a protein? Why is it never left on its own? And the answer to that, the
very important answer to that, is that when iron is left
alone, when it’s not bound to anything, it’ll float
around and it will steal single electrons from different molecules, and it’ll generate something
called free radicals. And free radicals are really damaging to cells and molecules. So that’s why whenever you
find iron in the blood, or whether you find it in the cells, it’s always bound to something. In the blood it’s bound
to this chaperone protein called transferrin, and inside the cells when it’s being stored, it’s bound to a chaperone protein called ferritin. So the storage form of
iron is called ferritin. OK, so now we know enough
to talk about iron studies. So if you suspect that somebody
has iron deficiency anemia, you go ahead and order iron studies. And these are some of the
values that would come back. So let’s talk about what
we’d see in a patient who’s iron deficient. So if the patient is iron
deficient, you’d expect their serum iron to be low, right? That’s not too hard to understand. What about their percent saturation? This refers to how many of
the sites on transferrin are occupied by iron. So if we’re in a state where
we’re deficient in ron, you’d expect that a lot of
the sites on transferrin are empty, they’re unoccupied by iron. And so the percent
saturation would be low. And it’s a good fact
to know that the normal percent saturation in a person
who isn’t iron deficient is 33 percent. So 33 percent of the
binding sites on transferrin are usually occupied by iron. Let’s look over the total
iron binding capacity for a second and talk about the ferritin. So in a person who’s iron
deficient, you’d expect that their ferritin, or the amount
of storage iron they have, is decreased, right? Maybe not initially so. Maybe when you initially
become iron deficient you start using up some
of your storage iron. But eventually, after a prolonged
period of iron deficiency, your storage iron, your
ferritin, would also decrease. Now let’s talk a little
bit about the total iron binding capacity. This value actually reflects
the amount of transferrin. Amount of transferrin. And that makes sense because
as your transferrin goes up, the amount, the binding capacity
you have for iron goes up. And as the amount of
transferrin you have goes down, the binding capacity of iron goes down. So our body does this
really cool thing where it recognizes that it is deficient in iron. And it tries to compensate for that by making more transferrin
so that the transferrin can go out into the bloodstream and suck up more of this iron. So as a compensatory
mechanism in iron deficiency, your transferrin levels,
and hence your total iron binding capacity actually increases, OK? This is really important. This is our body’s main
mechanism for combating the iron deficiency. So if these iron studies
came back with these values, you could definitively
say that your patient has iron deficiency anemia. But that tells you nothing about
why they’re iron deficient. So the last step would be to determine why the patient is iron deficient. So let’s slide over and
take a look at this. You may remember we created this chart to sort of highlight the main
causes of iron deficiency anemia. So as your last step, you’d take a look at the patient’s age and their gender and see what could the possible
cause of iron deficiency be. If you have a woman who’s
pregnant, well you could speculate it’s probably because
of the increased demand that she’s iron deficient. If you have a woman who
experiences heavy menstrual flow, then menorrhagia would be the reason, and perhaps explore that further. You could do an ultrasound
of the uterus, of the pelvis to see maybe if there are fibroids present that are accounting for the
increased menstrual flow. In a young man, or even in a young woman, who’s experiencing
signs of gastric reflux, you might say, well perhaps
peptic ulcer disease is present, and you could do an
endoscopy, which is inserting a camera through the mouth
to take a look at the esophagus and the stomach
for the presence of ulcers to account for the iron deficiency. And in elderly people,
very, very importantly, you always have to consider
colon cancer or colon polyps as the cause of iron deficiency anemia. So if an elderly individual
walks in with new onset iron deficiency anemia,
you should always do a hemoccult test, a hemoccult test. And what that looks for is blood in stool. So it tests the stool for
the presence of blood. And if that’s positive, if
you find blood in the stool, then you can do a colonoscopy,
which is inserting a camera through the colon to look for
a possible cancer of a polyp. So these are some of the common causes of iron deficiency anemia, and
these are the three steps that we just went through,
are the three steps you’d go through to diagnose someone with iron deficiency anemia.

About James Carlton

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29 thoughts on “Iron deficency anemia diagnosis | Hematologic System Diseases | NCLEX-RN | Khan Academy

  1. I love this channel so much and I love this lady omg whoever you are thank you so much for simplifying such complex topics (I was banging my head on my pathology book a few minutes ago!) This is a great initiative, forever grateful to Khan academy from high school to all the way to third year of medical school. <3

  2. What if your transferrin is low and your ferritin is low? Thank you for explaining this in plain English for us who aren’t studying medicine and who are anemic 😊

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