Author Topic: What causes blood pressure?  (Read 2170 times)

Offline surfivor

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What causes blood pressure?
« on: January 23, 2020, 08:04:52 PM »
When I google what causes blood pressure I just get hits on high blood pressure. I am trying to understand at a more basic level.

Is the body like a tire that is inflated so that if there is high blood pressure then it is overinflated? I don’t exactly understand what the mechanics are or why exercise or eating habits would effect it. If the tire analogy made sense then just as there is too much air in the tire then there must be too much blood but that doesn’t seem likely to be the answer

High blood pressure is also called hypertension. When I think of a tire that is inflated, would I consider that tire to have tension ? Isn’t tension more like a rope that is bound tightly or a bow that is pulled back to release an arrow? When I think of tension I think of maybe I have a headache but does having a headache mean your blood pressure went up ?

I was also experimenting with my mothers blood pressure meter but the readings are all over the place. I took 4 different readings and they all where totally different, high low, all over the place. I don’t exactly understand why that would be either

Does it reflect how hard the heart is pumping? But I am not sure how that would differ from the pulse rate

It also sounds like half the adult population in the US would have high blood pressure according to the medical establishment
« Last Edit: January 23, 2020, 08:17:18 PM by surfivor »

Offline surfivor

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Re: What causes blood pressure?
« Reply #1 on: January 23, 2020, 08:25:34 PM »
I looked up how the meter works. I guess it’s more like pressure in a pipe or faucet

Offline Carver

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Re: What causes blood pressure?
« Reply #2 on: January 23, 2020, 09:57:35 PM »
Physically my understanding is that constrictions in the arteries play a role in pressure, think stepping on a garden hose. If there is more constriction the pump has to work harder, has less time between pumps to relax. Reducing restrictions lowers blood pressure. The higher number is the resistance and the lower is the relaxation.

Offline FreeLancer

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Re: What causes blood pressure?
« Reply #3 on: January 24, 2020, 04:54:57 AM »
There’s a lot of moving parts involved with maintaining blood pressure.  The heart is specialized muscle tissue that can vary its rate and strength of contraction based on hardwired autonomic nervous system control and/or hormones, like adrenaline, released into the blood stream. Similar control systems cause the smooth muscle in blood vessels to contract or relax so blood flow is optimized in the organs needed to survive whatever the situation demands. Then there’s the volume of fluid in the entire circulatory system which is a function of what the organism can absorb from the environment and what the kidney and gut can hang onto while getting rid of waste products. And bleeding....

Offline surfivor

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Re: What causes blood pressure?
« Reply #4 on: January 24, 2020, 11:22:26 AM »
The term hypertension is usually also applied to high blood pressure. It seems to imply if you have high blood pressure then it would effect how you feel because hypertension seems to have an implication of being stressed. I am not sure if that is true however or if the term could be somewhat deceptive or inaccurate

Offline FreeLancer

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Re: What causes blood pressure?
« Reply #5 on: January 24, 2020, 02:25:33 PM »
Hypertension is a silent disease, meaning you typically aren't aware of it, because blood pressure has to be extremely high to produce symptoms.

There is no psychological connotation associated with the use of the "tension" root word when describing blood pressure in physiology or medicine.  It's strictly referring to the physical property of pressure within the circulatory system, which is measured in mmHG (the height of a column of mercury).

Offline Strengthfarm

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Re: What causes blood pressure?
« Reply #6 on: August 05, 2020, 02:44:06 PM »
So there are many things that affect blood pressure. The rate, rhythm, stretch, and contration force of the heart, the hydration level of the patient, function of kidneys, condition of the vessels (arteries can actually contract and dilate, vessels have one-way valves and rely on muscle contraction to help squeeze blood back to the heart) and the position of the patient (orthostatic hypotension is present in many geriatric patients).

Also, the cuff should be properly sized and positioned, in line with the heart and the extremity should be relaxed. There will be a index mark which should be aligned with the major artery.




Understand when talking about the circulatory system, it is composed of 2 pumps, a low pressure pump and a high pressure pump. The body just places them together to make things easier.

First thing to understand is the top number (systolic) is the systemic resistance to blood flow when the heart contracts. The bottom (diastolic) is the resting pressure exerted against the walls of the circulatory system.

Then you have pulse pressure (S-D=PP).

A very narrow pulse pressure (<30mmHg) is concerning because it indicates your heart isn't functioning properly. There could be a number of causes but the mortality rate is quite high.

A wide pulse pressure indicates (>70mmHg) is concerning because it indicates that the vessels themselves aren't stretching properly. This eventually leads to the heart working too hard and growing to become stronger. Initially this allows it to beat harder, but it grows like a normal muscle and the space inside the heart actually shrinks as the heart grows, forcing the heart to beat harder and harder. Eventually you'll end up with LVH (left ventricular hypertrophy) and the output will be reduced no matter how hard and fast the heart pumps.

If someone is suddenly in a hypertensive crisis and stroke symptoms, it is important not to suddenly significantly drop their blood pressure. The reason is, they may be having a stroke and the hypertension is a protective mechanism to overcome the increased ICP (intra-cranial pressure) and CPP (Cerebral Perfusion Pressure) will be MAP (Mean Arterial Pressure, arguable the most important number to track) - ICP.

Some things to note, the heart receives blood during diastole, so, while most people don't pay attention to DBP, it actually is important.
 
MAP = [(2 x diastole) + systole] / 3  is actually probably the most important number to track.

Offline surfivor

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Re: What causes blood pressure?
« Reply #7 on: August 11, 2020, 11:59:51 PM »
I wonder if it is useful to get a blood pressure gauge to measure your own blood pressure ? How accurate or reliable are these things if you get them at the drug store ? I heard they changed blood pressure recommendations some time ago. I am not interested in taking statin drugs or the like but I have an interest in studying health parameters. Blood pressure seems like a fairly basic type of thing. I tend to not go to the doctors but I have an interest in studying aspects of health on my own

I think I also recalled reading that the number of adults with supposed high blood pressure is very high

Offline CarbideAndIron

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Re: What causes blood pressure?
« Reply #8 on: August 12, 2020, 02:42:49 PM »
Survivor,
I got my own monitor from like Rite Aid or Walgreens, can't recall which. But it's important to check yours like right when you wake up, or at a time when you're at rest, and haven't just done anything to get the heart rate up. Just like checking your resting heart rate, which is another rabbit hole you might want to look into.
But you want to use the same one, and I personally don't like the drug store ones because they get abused. You want something you know is in proper working condition. There will be a variance from one monitor to the next, so consistency is key here if you want to track progress.

Offline CarbideAndIron

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Re: What causes blood pressure?
« Reply #9 on: August 12, 2020, 02:46:02 PM »
Survivor,
So there are many things that affect blood pressure. The rate, rhythm, stretch, and contration force of the heart, the hydration level of the patient, function of kidneys, condition of the vessels (arteries can actually contract and dilate, vessels have one-way valves and rely on muscle contraction to help squeeze blood back to the heart) and the position of the patient (orthostatic hypotension is present in many geriatric patients).

Also, the cuff should be properly sized and positioned, in line with the heart and the extremity should be relaxed. There will be a index mark which should be aligned with the major artery.




Understand when talking about the circulatory system, it is composed of 2 pumps, a low pressure pump and a high pressure pump. The body just places them together to make things easier.

First thing to understand is the top number (systolic) is the systemic resistance to blood flow when the heart contracts. The bottom (diastolic) is the resting pressure exerted against the walls of the circulatory system.

Then you have pulse pressure (S-D=PP).

A very narrow pulse pressure (<30mmHg) is concerning because it indicates your heart isn't functioning properly. There could be a number of causes but the mortality rate is quite high.

A wide pulse pressure indicates (>70mmHg) is concerning because it indicates that the vessels themselves aren't stretching properly. This eventually leads to the heart working too hard and growing to become stronger. Initially this allows it to beat harder, but it grows like a normal muscle and the space inside the heart actually shrinks as the heart grows, forcing the heart to beat harder and harder. Eventually you'll end up with LVH (left ventricular hypertrophy) and the output will be reduced no matter how hard and fast the heart pumps.

If someone is suddenly in a hypertensive crisis and stroke symptoms, it is important not to suddenly significantly drop their blood pressure. The reason is, they may be having a stroke and the hypertension is a protective mechanism to overcome the increased ICP (intra-cranial pressure) and CPP (Cerebral Perfusion Pressure) will be MAP (Mean Arterial Pressure, arguable the most important number to track) - ICP.

Some things to note, the heart receives blood during diastole, so, while most people don't pay attention to DBP, it actually is important.
 
MAP = [(2 x diastole) + systole] / 3  is actually probably the most important number to track.



Wow, talk about hell of a first post. Thanks Strength, I felt I had a good basic understanding of it, but this was gold.

Offline Knecht

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Re: What causes blood pressure?
« Reply #10 on: September 24, 2020, 04:54:46 AM »
I don't know much about blood pressure (certainly nothing to add to what has already been said), but I know a good natural remedy when you need to lower it: hawthorn. Blossoms seem to work best (pick them early, while they're starting to open), berries somewhat less, young leaves are the third and weakest option. It takes time to make it work, don't expect instant effect. Drink hawthorn tea for a couple weeks to settle your hearth. You can also make tincture if you macerate about 100g berries in 0,5l of alcohol (volume 50% or more) If you have some serious hearth problems or take any synthetic drugs for it, you should consult with a doctor though. Do NOT use it along with digitalis (foxglove)!

Offline Gamer

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Re: What causes blood pressure?
« Reply #11 on: October 06, 2020, 03:48:05 AM »
True story- my neighbour was about 65 years old and had high blood pressure, possibly because he was highly strung and a right misery-guts, always arguing with people with a face as sour as sh*t.
Once he went ballistic at me because he didn't like me feeding pigeons on my windowsill, and as he ranted his face literally turned purple and nearly black!
He died of a brain haemorrhage a few years ago and I can't help thinking that if he'd learnt to relax more, he'd still be alive today..