Hypertension symptoms and categories | Health & Medicine | Khan Academy
Hypertension symptoms and categories | Health & Medicine | Khan Academy
Learn the most common symptoms (or lack thereof!) and the two major categories of hypertension. Rishi is a pediatric infectious disease physician and works at Khan Academy. Created by Rishi Desai.
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Content
2.52 -> All right.
3.02 -> Let's talk about hypertension.
5.38 -> And the first
thing we have to do
8.18 -> is understand the two
main categories, or types,
12.78 -> of hypertension
that are out there.
14.28 -> So there are two
types, primary--
20.58 -> and this is actually also
called essential hypertension.
23.06 -> You might hear that
word, essential.
25.64 -> And secondary.
27.21 -> And I'll write that as a two.
29.21 -> And so the way that
this is divided up
32.03 -> is that primary hypertension is
caused by something indirect.
40.91 -> OK, so what does
that mean exactly?
43.087 -> So I'll give you
some examples of what
44.67 -> the indirect cause could be.
46.41 -> It could be something
like smoking,
48.38 -> or it could be that someone
has obesity or is obese.
53.35 -> Or it could be that they
have hyperlipidemia,
57.11 -> meaning that they have lots
of fats floating around
60.88 -> in the blood.
62.55 -> Or let's say they have diabetes.
64.129 -> That would be another
cause, or indirect cause,
68.36 -> of hypertension.
69.54 -> And these are all
risk factors, right?
71.26 -> That's another way of
thinking about these things.
73.343 -> These are general risk factors
for having hypertension.
76.96 -> And the other category
would be something direct.
80.684 -> And once I write
this down, you'll
82.1 -> start seeing the difference.
83.38 -> This would be something
like kidney disease.
86.51 -> So let's say that I have
a problem with my kidneys.
90.4 -> And they, for some
reason-- these
92.42 -> are my kidneys--
they are holding on
94.24 -> to far too much fluid
than they should.
96.73 -> And that's because
they're diseased.
98.85 -> And so they're holding
onto too much fluid.
100.74 -> And they're causing my
volume of blood to go up.
103.864 -> There causing the
volume to go up,
105.28 -> and the stroke volume
is going up as well.
108.26 -> And if the stroke
volume goes up,
109.96 -> you know that stroke volume is
going to cause a higher blood
115.24 -> pressure, because
they're directly related
116.99 -> to each other-- very direct.
118.6 -> That would be one example.
120.3 -> Another example
could be-- let's say
121.93 -> I have what's called an
"aortic coarctation."
127.39 -> So this is a very
specific problem.
131.1 -> This would be-- if I have my--
let's say the heart is here.
135.32 -> And I have the aorta
coming off here.
138.63 -> Normally, it should be nice and
open, the way I've drawn it.
141.13 -> But if you have a
coarctation, then you
144.31 -> might have a pinching
in of the vessel.
147.46 -> So it would start
looking like this.
149.65 -> It would look like
that, like a pinch.
153.26 -> And if you have a pinching
in right there, then
156.92 -> you have increased resistance.
161.099 -> And if you have
increased resistance,
162.64 -> you know, again,
resistance is going
164.7 -> to relate back to pressure.
166.39 -> So if you have more resistance,
you have higher pressure.
169.29 -> So these are direct
causes of hypertension,
174.06 -> which is slightly different
than the indirect causes
176.29 -> I wrote above-- the
smoking, obesity--
178.22 -> because there's no clear
direct mechanism in any
181.264 -> of those things.
181.93 -> They're just more
general risk factors.
183.62 -> So this is how we kind of
divvy up the two groups.
185.92 -> And we say, OK, if you
have one or the other,
188.79 -> then you're in the primary
or secondary group.
191.85 -> So let's figure out, of the
two, which is more prevalent.
199.75 -> And this basically
means, which is
202.94 -> going to affect more people
at any point in time.
206.2 -> So if I was to poll all
people with hypertension--
209.81 -> ask them, hey, what group are
you in, primary or secondary--
213.62 -> most people would say primary,
because most of these people
218.48 -> are going to be smokers or obese
or diabetics or people that
223.59 -> have hyperlipidemia, some
of these risk factors
226.3 -> that we just laid out.
227.22 -> In fact over, 90% of the people
have primary hypertension.
235.13 -> And only a few people, I
would say less than 10%,
239.23 -> are going to say,
nope, I'm actually
240.88 -> in the secondary group.
241.9 -> I have a very specific reason
for having hypertension.
245.332 -> So this is actually
a very easy way
246.79 -> of figuring out if people
are having hypertension
250.1 -> from an indirect cause
or a direct cause.
253.01 -> All right.
253.75 -> So now, let's assume
that you follow
256.57 -> one person over
time, one individual.
259.57 -> And that person used to
have normal blood pressure.
264.08 -> Let's say this is blood
pressure over here.
266.27 -> And I'm going to write it out
as Mean Arterial Pressure, MAP.
270.58 -> Mean Arterial Pressure.
272.56 -> And we want to maintain a
Mean Arterial Pressure, a MAP,
277.27 -> of a certain number.
278.242 -> So this would be like a normal
blood pressure range, right?
280.7 -> Something below
this dashed line.
283.89 -> So this is normal.
286.69 -> But of course, many people have
something higher than normal.
289.78 -> They, over time, might
develop higher blood pressure.
294.63 -> So maybe they start out here
and here in the normal range.
298.63 -> And then they start having
high blood pressure.
301.41 -> And it kind of goes up and
down, and up and then down
304.73 -> and stops there.
306.94 -> So in this person--
I'm going to connect
310.24 -> the dots-- they,
if you asked them,
313.29 -> would not have any symptoms
for most of the time.
316.38 -> They would actually say,
you know, I feel fine.
319.04 -> I don't have any
symptoms at all.
320.5 -> In fact, up until
this point in time,
325.139 -> they would say they
have no symptoms.
329.5 -> And the vast majority of people
are actually in this group.
332.72 -> So most people
with hypertension,
334.37 -> if you ask them if they
have symptoms from it,
336.32 -> they would say no, they
don't have any symptoms.
338.73 -> But at some point, they
can develop symptoms.
341.77 -> Not everybody, but you
can develop symptoms.
344.18 -> And when you do, it's
usually quite significant.
347.43 -> So you might have
problems with your heart.
350.58 -> Maybe your heart is having
to work harder than it ever
353.05 -> had to, and you're having
some heart failure.
355.67 -> Or you might have problems
with your large vessels
359.11 -> or medium vessels.
361.05 -> And primarily, these
are the arteries,
363 -> because the arteries
are the vessels that
365.095 -> are seeing those high pressures.
366.82 -> And those arteries might
be getting very stiff.
370.1 -> Or you might have problems
with tiny vessels.
372.95 -> These are the little
arteries, the smallest ones,
375.78 -> or the arterioles.
377.01 -> And remember, the smallest
arteries and arterioles,
379.86 -> they're not sitting
there naked in your body.
383.34 -> They're usually within
an organ, right?
386.2 -> So they're usually
within the kidney,
388.89 -> or they could be within the eye.
390.79 -> So I'll just draw these two.
392.89 -> So they're usually
within some other organ.
395.58 -> And if you have problems with
the smallest arterioles-- let's
398.87 -> say they're breaking-- then
really, what you're saying
402.44 -> is you're going to have kidney
problems or eye problems.
405.73 -> So these are the kind
of problems you can get.
408.58 -> And because most
people are having
410.39 -> no symptoms-- most
people are over here--
412.76 -> you really want to catch
them before they cross over
416.08 -> from no symptoms
to having symptoms.
418.74 -> And you want to take care of
the blood pressure problem
421.174 -> so that they never
develop any symptoms.
422.84 -> That's the goal.
424.57 -> Now, unfortunately,
some people develop
427.02 -> what's called "malignant
hypertension."
430.124 -> And I'm going to
write out for you
431.54 -> what malignant
hypertension means.
436.13 -> It's a few things.
438.41 -> And we can actually even
draw it on our figure.
440.54 -> Maybe I'll do that.
441.65 -> So you have people with
malignant hypertension
444.05 -> that have a rapid rise
in their blood pressure.
450.03 -> And it causes damage to
the heart and vessels.
461.97 -> And finally, the range
that we're talking about,
465.35 -> it's a rapid rise to a
really high blood pressure.
468.18 -> Sometimes we think
of these pressures
470.37 -> being around 240 over 120--
really high blood pressures.
474.06 -> So on our graph, this
could be the person
476.08 -> that-- unlike the
person in white,
478.41 -> this person maybe had a
very quick rise in pressure.
484.92 -> And then it got very high,
maybe got up to 240 over 120.
490.94 -> And so this would
be the third point.
493.66 -> The rapid rise is
the first point.
496.09 -> And the fact that they're having
symptoms is point number two.
499.84 -> So you can see now how someone
with malignant hypertension
503.55 -> could look on this
sort of a graph.
Source: https://www.youtube.com/watch?v=8aeivxR1GDc