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Current time:0:00Total duration:4:33

Video transcript

so let's just say that you go in for your annual physical exam and you're told that you have hypertension well what does that mean and why could this be a problem for you well hypertension is another term we use to describe high blood pressure so the pressure inside your blood vessels is too high or the blood that's moving around inside them is under a higher pressure than normal to sort of illustrate that let's think about your circulatory system instead is like this plumbing system so you've got a pump that moves water around the pump in your heart and the water being blood and the pumps pumping blood out to both your lungs and your body and then receiving that blood back in and so the pumping out part are like your arteries going away from your heart and then the pumping in part are like your veins in both of these pipes the in and the out or your veins and your arteries have a certain amount of pressure so here going out we have arterial pressure or pressure in the arteries and then here coming into the pump we have venous pressure since the arterial side is what the heart's pumping out into if the pressure on that side is too high it gets a lot harder for your heart to pump more blood out and usually this means that the heart has to do more work because it's pumping against higher pressures right now there are a lot of things that can make the pressure in the pipes higher and therefore make the pump work harder but the two main things that we're going to focus on are called flow and resistance and the flow is how we describe the movement of a volume of fluid so how the water moves through the pipes or in our case the blood circulating around the body when there's more fluid or flow trying to circulate in the same space the pressure is going to be higher right think of if you turned up the faucet to this system all the sudden we're trying to get more water out through the same sized pipes so now those pipes are going to be under a higher pressure but how do we turn up the faucet how do we get this increased flow or increased blood volume circulating around the body well it's usually because your kidneys are making you hold on to more fluid since one of your kidneys main jobs is to regulate the fluid in your body it could also be because there's more salt in your blood vessels fluid tends to move to areas with more salt so more salt in the blood vessels means more fluid in the blood vessels and this is also why a diet high in salt can contribute to high blood pressure okay so that was flow resistant on the other hand is like how hard it is for fluid to move through the blood vessels the higher the resistance just like the flow the higher the blood pressure now this could simply mean just like a change in the size of the pipes and by size i mean diameter so as the diameter gets smaller you have a higher resistance in the pipes and so your blood pressure goes up so think of like a hose that's just open the water sort of just falls out right there's not a lot of pressure pushing it out is there well what if you put a small nozzle on it all of a sudden you've got this serious super soaker on your hands right that's because the smaller diameter nozzle is putting a lot more pressure on the water it's the same with a blood vessel that gets smaller the Bloods going to be under a higher pressure whenever your blood vessels squeeze we call that vasoconstriction and vasodilation the vessels get bigger we call it vasodilation because they're dilating and getting bigger now higher resistance could also be caused by your arteries becoming too stiff which can happen as a result of aging or a buildup of fatty deposits this buildup is referred to as atherosclerosis so you've got blood moving through here and then these build-up start to happen or sometimes we just call it plaque and that plaque accumulates and in addition to making that opening that the blood can move through in the vessels smaller in diameter it also makes the blood vessels as a whole less flexible and more stiff healthy arteries have a certain amount of elasticity to them meaning they're a little bit elastic so maybe when more blood moves through them they stretch just a little bit to allow that additional blood flow if they lose that elasticity and become stiff then they won't stretch as much and so the resistance goes up and also your blood pressure goes up