Hypertension symptoms and categories | Health & Medicine | Khan Academy

Hypertension symptoms and categories | Health & Medicine | Khan Academy


All right. Let’s talk about hypertension. And the first
thing we have to do is understand the two
main categories, or types, of hypertension
that are out there. So there are two
types, primary– and this is actually also
called essential hypertension. You might hear that
word, essential. And secondary. And I’ll write that as a two. And so the way that
this is divided up is that primary hypertension is
caused by something indirect. OK, so what does
that mean exactly? So I’ll give you
some examples of what the indirect cause could be. It could be something
like smoking, or it could be that someone
has obesity or is obese. Or it could be that they
have hyperlipidemia, meaning that they have lots
of fats floating around in the blood. Or let’s say they have diabetes. That would be another
cause, or indirect cause, of hypertension. And these are all
risk factors, right? That’s another way of
thinking about these things. These are general risk factors
for having hypertension. And the other category
would be something direct. And once I write
this down, you’ll start seeing the difference. This would be something
like kidney disease. So let’s say that I have
a problem with my kidneys. And they, for some
reason– these are my kidneys–
they are holding on to far too much fluid
than they should. And that’s because
they’re diseased. And so they’re holding
onto too much fluid. And they’re causing my
volume of blood to go up. There causing the
volume to go up, and the stroke volume
is going up as well. And if the stroke
volume goes up, you know that stroke volume is
going to cause a higher blood pressure, because
they’re directly related to each other– very direct. That would be one example. Another example
could be– let’s say I have what’s called an
“aortic coarctation.” So this is a very
specific problem. This would be– if I have my–
let’s say the heart is here. And I have the aorta
coming off here. Normally, it should be nice and
open, the way I’ve drawn it. But if you have a
coarctation, then you might have a pinching
in of the vessel. So it would start
looking like this. It would look like
that, like a pinch. And if you have a pinching
in right there, then you have increased resistance. And if you have
increased resistance, you know, again,
resistance is going to relate back to pressure. So if you have more resistance,
you have higher pressure. So these are direct
causes of hypertension, which is slightly different
than the indirect causes I wrote above– the
smoking, obesity– because there’s no clear
direct mechanism in any of those things. They’re just more
general risk factors. So this is how we kind of
divvy up the two groups. And we say, OK, if you
have one or the other, then you’re in the primary
or secondary group. So let’s figure out, of the
two, which is more prevalent. And this basically
means, which is going to affect more people
at any point in time. So if I was to poll all
people with hypertension– ask them, hey, what group are
you in, primary or secondary– most people would say primary,
because most of these people are going to be smokers or obese
or diabetics or people that have hyperlipidemia, some
of these risk factors that we just laid out. In fact over, 90% of the people
have primary hypertension. And only a few people, I
would say less than 10%, are going to say,
nope, I’m actually in the secondary group. I have a very specific reason
for having hypertension. So this is actually
a very easy way of figuring out if people
are having hypertension from an indirect cause
or a direct cause. All right. So now, let’s assume
that you follow one person over
time, one individual. And that person used to
have normal blood pressure. Let’s say this is blood
pressure over here. And I’m going to write it out
as Mean Arterial Pressure, MAP. Mean Arterial Pressure. And we want to maintain a
Mean Arterial Pressure, a MAP, of a certain number. So this would be like a normal
blood pressure range, right? Something below
this dashed line. So this is normal. But of course, many people have
something higher than normal. They, over time, might
develop higher blood pressure. So maybe they start out here
and here in the normal range. And then they start having
high blood pressure. And it kind of goes up and
down, and up and then down and stops there. So in this person–
I’m going to connect the dots– they,
if you asked them, would not have any symptoms
for most of the time. They would actually say,
you know, I feel fine. I don’t have any
symptoms at all. In fact, up until
this point in time, they would say they
have no symptoms. And the vast majority of people
are actually in this group. So most people
with hypertension, if you ask them if they
have symptoms from it, they would say no, they
don’t have any symptoms. But at some point, they
can develop symptoms. Not everybody, but you
can develop symptoms. And when you do, it’s
usually quite significant. So you might have
problems with your heart. Maybe your heart is having
to work harder than it ever had to, and you’re having
some heart failure. Or you might have problems
with your large vessels or medium vessels. And primarily, these
are the arteries, because the arteries
are the vessels that are seeing those high pressures. And those arteries might
be getting very stiff. Or you might have problems
with tiny vessels. These are the little
arteries, the smallest ones, or the arterioles. And remember, the smallest
arteries and arterioles, they’re not sitting
there naked in your body. They’re usually within
an organ, right? So they’re usually
within the kidney, or they could be within the eye. So I’ll just draw these two. So they’re usually
within some other organ. And if you have problems with
the smallest arterioles– let’s say they’re breaking– then
really, what you’re saying is you’re going to have kidney
problems or eye problems. So these are the kind
of problems you can get. And because most
people are having no symptoms– most
people are over here– you really want to catch
them before they cross over from no symptoms
to having symptoms. And you want to take care of
the blood pressure problem so that they never
develop any symptoms. That’s the goal. Now, unfortunately,
some people develop what’s called “malignant
hypertension.” And I’m going to
write out for you what malignant
hypertension means. It’s a few things. And we can actually even
draw it on our figure. Maybe I’ll do that. So you have people with
malignant hypertension that have a rapid rise
in their blood pressure. And it causes damage to
the heart and vessels. And finally, the range
that we’re talking about, it’s a rapid rise to a
really high blood pressure. Sometimes we think
of these pressures being around 240 over 120–
really high blood pressures. So on our graph, this
could be the person that– unlike the
person in white, this person maybe had a
very quick rise in pressure. And then it got very high,
maybe got up to 240 over 120. And so this would
be the third point. The rapid rise is
the first point. And the fact that they’re having
symptoms is point number two. So you can see now how someone
with malignant hypertension could look on this
sort of a graph.