What is hypertension? Learn the categories of hypertension for systolic and diastolic blood pressures. Rishi is a pediatric infectious disease physician and works at Khan Academy.
What is hypertension?
- Let's talk about hypertension, I'll write that here: hypertension
- And hypertension basically means high blood pressure
- and we actually categorize it in different groups. So let's use my blood pressureof 115/75 as an example
- And I had drawn thisfigure for where where I had blood pressure on this side
- and I had time on this side.
- And I said my blood pressure does something like that
- where the peak is 115
- this is the systolic blood pressure
- and I said that the lowest point is 75.
- And that was my diastolic blood pressure.
- We know that everyone has a different blood pressure, so let's organize blood pressure
- into groups. let's say what group goes where
- so to do that I'm gonna draw a couple number lines.
- So I have here in brown, I'll do my systolic blood pressure
- on this side and I'll do the diastolic on the other side.
- And we're going to actually put them next to eachother
- and I'll try to make them about the same size
- like that. So let's say this is really high pressure
- This would be like 200, and this is all in millimeters of mercury (mmHg).
- 200 mmHg. and at the very bottom would be zero.
- So let's make them kind of the same.
- And that means that up here would be about 100
- and this would be about 120, this about 140,
- let's say this is maybe 160, and this is 180.
- And I'm gonna do the same thing here, this is about 100.
- Except I'm gonna go on the other side.
- Let's say this is about 80, and this is 60, 40, 20
- Maybe I didn't draw it as well, but I think you get the idea.
- So this is my number line, and the reason I drew the systolic numbers higher
- than the diastolic is that we know the systolic pressure is always going to be higher than the diastolic pressure.
- So that is why I separated it out. But you can imagine that
- these numbers go up and these go down
- I'm just being lazy and not drawing it all out.
- So let's say that my pressure is 115, this is my systolic pressure.
- let's do that one first. Where does that fit?
- Well on this number line, 115 would be about right here.
- And actually anything below 120 is kind of in the green zone
- and this goes all the way down to zero
- So let's say my systolic was 97 or 103, that would all be in the green zone.
- And what I mean by that is I would say that I do not have hypertension.
- So that's kind of a nice, safe area to have your blood pressure in terms of hypertension.
- Now for diastolic pressures, we know that diastolic pressures are
- the low range of a blood pressure.
- And so those numbers are going to be lower.
- Here, anything below 80 is considered in that green zone
- Below 80 is where you want to be.
- And I want to be very specific, I don't mean to say that
- a blood pressure of 5 would be good.
- What I mean is that you don't have hypertension, so you don't have HIGH blood pressure.
- And that's very different from having low blood pressure.
- So just for right now the green zone in terms of high blood pressure.
- Now let's say my systolic blood pressure was a little bit higher
- say it's between 120 and 140, somewhere in here
- then I'm in the yellow zone, and that yellow zone means that
- I don't have hypertension, but I'm getting there, so I'm getting closer
- and this would be "Pre-hypertension"
- On the other side, on the diastolic side, we use 90 as a cut-off
- I'll write in 90, and anything between 80 and 90 would be
- kind of in that yellow zone, and that's your pre-hypertension zone
- That's pre-hypertension, so you're still not there yet.
- Now in terms of high blood pressures, again you don't want high blood pressures
- but in terms of getting there, if you're above 140
- you're in hypertension, this zone right here
- 140-160 in particular is considered stage 1 hypertension
- and between 90-100 for diastolic is stage 1.
- And now if you have something above 160 for systolic blood pressure
- Above 160, even higher than 200, so let's say you have 201,
- that'd be stage 2.
- So you can see that the higher you go, the higher your stage number
- and the same is true on this side(diastolic).
- So let's say you have a really high diastolic, well above 100,
- you'd have stage 2 hypertension
- all the way down there, so this is stage 2.
- So i'm just gonig to do a couple quick examples for you.
- So let's say, I'll do them in yellow (different color).
- So let's say that you have 145 as a systolic and your diastolic is, let's say, 87.
- Well 145 is right here, and 87 (I'm gonna do it in the same color to be consistent)
- 145 is right here, and 87 is in here.
- So you're systolic is stage 1 hypertension, and your diastolic is in pre-hypertension.
- So when you're in different stages for the diastolic and the systolic, what you do,
- the rule is that you go with the higher stage.
- So in this case, stage 1 is higher, so this person would be considered stage 1 hypertension.
- Now we can do one more example, just to make sure you get it.
- So let's do a different color, I'll do the next one in red.
- So let's say you have 126 over 101.
- So this person, 126 is actually right here, and 101 is right above the 100 mark right there.
- So this person is actually pre-hypertensive if you're looking at just your systolic value,
- but they're actually in stage 2 hypertension if you're looking at their diastolic value.
- So overall, they're going to be in stage 2.
- Becaseu the rule, again, is that you go with the higher stage.
- So that's how you figure out what stage of hypertension someone is in.
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