Health and medicine
- What is hypertension?
- Intro to hypertension (Pressure, flow, and resistance)
- Intro to hypertension (systolic and diastolic blood pressure)
- Stages of hypertension
- Hypertension types and causes
- Primary hypertension
- Secondary hypertension
- Hypertension effects on the blood vessels
- Hypertension and blood vessel damage
- Hypertension effects on the heart
- Hypertension and heart damage
- Complications of hypertension
- Hypertensive crisis
- Diagnosis of hypertension
- Treatment of hypertension
- 4 lifestyle changes to help manage hypertension
Learn about how hypertension can cause damage to the large/middle sized arteries as well as the small arteries and arterioles. Rishi is a pediatric infectious disease physician and works at Khan Academy. Created by Rishi Desai.
Want to join the conversation?
- @4:07Is the body able to repair an aneurysm or is surgery required to repair it?(5 votes)
- Can people get aneurysms in the veins and if so are they called something different? Are the aneurysms in the the small arteries just as life threatening as the ones in the large arteries over time? When a doctor does surgery on an aneurysm, does he just cut it out and stitch it up or does he need to graft on a piece of tissue? Is it possible to reverse or control Arteriosclerosis with or without lowering blood pressure?(4 votes)
- Arterial aneurysms is more common due to higher pressure, but venous aneurysms can occur.
Treatment is based on location and size. For example small aneurysms in the brain, can be "coiled", meaning the surgeon fill it with a thin thread, untill it is completely closed, and leave it with that. Bigger aneurisms in the abdomen is often cut open, and a graft made of for example gore-tex is placed inside the artery before it is closed again.
Blood pressure control (lowering blood pressure if high) will help against developing arteriosclerosis, amongst other things.(5 votes)
- an aneurysm in the brain for example should be very dangerous.
is it common?(2 votes)
- Doing a quick Google search for "cerebral aneurysm incidence rates" showed that the most common estimate is approximately 30,000 ruptured brain aneurysms a year in the US, with somewhere around ~40% being fatal.(1 vote)
- what are the symptoms of hypertension?(1 vote)
- A headache is a common symptom that many people ignore, or try to treat themselves with tylenol or advil, but is actually a symptom of their hypertension.(2 votes)
- can you have hemorrhage from an artery that is arteriosclerotic? in the sense of an aneurism but i imagine it like a crack in a pipe?(1 vote)
- Yes, something called a dissection can cause the "crack" that you are thinking about and blood can track between parts of wall of the blood vessel. The other thing that can happen is an aneurysm. Otherwise, it's not common to have them just rupture and hemorrhage.(1 vote)
- Is arteriosclerosis and atherosclerosis the same thing? I thought arteriosclerosis was the buildup of plaque in the arteries..does the term include both plaque buildup and he hardening/stiffening of arteries?(1 vote)
- After hypertension becomes controlled by medication, are any of its effects reversible over time? (Not anerysms, but lesser damage such as wear of the vessel linings or stiffening of the arteries...)(1 vote)
- @2:33, HOW do arteries eventually lose their elasticity and become firm? does the high blood pressure erode away muscle that makes it elastic?(1 vote)
Now, we've talked about hypertension, and you know that it means that you have high blood pressure. So the next logical thing to think about is why is that bad? Why is it a problem to have high blood pressure? And I like to think about high blood pressure from two different perspectives-- one would be the perspective of the heart, and the other is the perspective of the blood vessels. And so here you can almost divide it up as the thing that's making the pressure or generating the pressure, which is the heart, and the thing that's receiving the pressure. So generating versus receiving pressure, and each of these two areas has some serious consequences for the body. So let's just divide it up here. Let's just draw a dashed line, divide up our screen, and we'll talk about both areas. So let's start with the receiving pressure side. So we have the large and middle sized arteries-- and specifically I mean arteries that are between, let's say, 25 millimeters in diameter all the way down to about one millimeter in diameter. So primarily these are the vessels that are going to get blood from the heart to the different organs that it needs to get to. And then you of course have the small arteries and arterioles. And these are going to be at the high end. They're going to be one millimeter. But they're going to go all the way down and get smaller and smaller to about 0.01 millimeters, so about 1/100 of the size. They're very tiny. And these are receiving pressure. Both of them are receiving pressure. These I'll draw as-- I'll leave the drawing up above, and these are kind of very, very narrow ones, right? So both of them are receiving the pressure, and they're going to have problems. So for example, if you have, let's say, a large or middle artery that is-- let me draw it in a different color. Let's say here it's very elastic-- over time if you keep exposing this elastic vessel or tube to high pressures, over time what would happen is this becomes very firm, like a pipe. So that's one change. And in fact, that change from being elastic to firm, we call that arteriosclerosis. I'll write that in white-- arteriosclerosis. And in fact, a very similar thing happens on the other side with the small arteries and arterioles. They also have very similar kind of change. They can go from being very elastic-- I'm trying to draw it so it's got some springiness. That's obviously kind of tricky to draw. These become very firm as well over time, and they lose that elasticity. And when it happens in the small arteries or arterioles, we call that arteriolosclerosis-- a very similar word, but slightly different-- arteriolo-- an extra L and an O-- sclerosis. So this is the difference, right? They're very similar things, kind of similar processes, but one is in the smaller arteries and one is in the larger and middle sized arteries. So this is one of the things that can happen when you have lots of high blood pressure constantly exposed to the vessels. They can become firm. OK, going back to the large and middle arteries, you also can have a situation-- I'll draw it here-- where you have an artery, let's say-- actually, let me write what it is first. You can have an aneurysm. And an aneurysm is where you have a vessel-- let's say this is my vessel, and it's taking blood through it. So blood is going through it. And because of the constant blood pressure that's going through this vessel, the wall starts to get weak. So at one spot, it starts to get weak. Let's say right here instead of being like that, it starts to look like this. And you get this little area of weakness. I'll try to draw it like that. And because it's weak, the blood will start going, and hitting, and bouncing off the walls, and making it a little bit bigger. So it looks like that. And over time, it might do this. It might become a big sack. And that's an aneurysm. And actually that aneurysm, if it's a sack of blood, can actually burst and break. And that blood can spill out, and we call that hemorrhage. So you can actually have an aneurysm because of a weak vessel wall. Now, looking at the small arteries or arterioles, you can also have, not necessarily aneurysms in the same way, but you can have breaking or hemorrhage. And here I want to show you or remind you that these vessels, these tiny ones anyway, they're usually not sitting out there on their own. They're usually within an organ. So this tiny vessel-- remember, it's one millimeter to a hundredth of a millimeter. So it's actually sitting inside of a kidney or sitting inside of an eye. And so these organs have inside of them these arterioles and small arteries. And so when they're in that situation, if you have a break, let's say-- actually, let me rewrite this slightly differently. If you have a break in the vessel, we actually get organ damage. So this could be because the vessel literally breaks right here and blood spills out. And it could also be because these tiny vessels are necessary to make the organ work. For example, the kidneys require that these small arteries and arterioles are working properly. And if they're not, you start getting some problems with being able to do the job of the kidney. And so you can get kidney damage. Or if it's in your eye, you can get what we call retinopathy, basically meaning that the retina is not working properly. So you can have kidney damage or retinopathy. You can have aneurysms, arteriosclerosis, or arteriolosclerosis. And these are all related to the fact that the blood vessels are breaking or they're becoming more firm. And this is all on the side of receiving pressure.