Difference Between Systolic and Diastolic

Edited by Diffzy | Updated on: August 09, 2022


Difference Between Systolic and Diastolic Difference Between Systolic and Diastolic

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So there are two numbers that make up your blood pressure reading (for example, 120/80). Now, the power exerted on the arteries as the heart rate is measured by systolic blood pressure, sometimes known as the top number. Moreover, the amount of pressure on the arteries while the heart is at rest is indicated by the diastolic blood pressure (the bottom number).

In this article, let’s understand the major differences between systolic and diastolic pressure.

Systolic vs Diastolic Pressure

The major distinction between systolic and diastolic numbers is that the former represents the highest or maximum amount of blood pressure that the heart can exert while breathing, while the latter represents the lowest level of pressure that the heart can achieve while beating.

Difference Between Systolic and Diastolic in Tabular Form

Table: Systolic vs Diastolic Pressure
Parameters of Comparison
Systolic Pressure
Diastolic Pressure
It measures the pressure that the heart exerts on the arteries as it pumps blood to the rest of the body.
It evaluates the blood pressure as the heart rests between beats.
The top number is the reading.
The lower number is the reading.
This is more important.
This is comparatively less important.
The normal blood pressure that is measured
Does it show frequent changes?
Yes, especially while the heart is working more.
The Age Factor
Systolic pressure tends to increase with age.
This pressure tends to decrease with age.

What is Systolic Pressure?

Now, a muscle the size of your fist makes up your heart. There are four chambers and four valves in it. The valves are open and close to allow blood to flow through the chambers and into and out of your heart. Your heart beats 60 to 100 times each minute, or around 100,000 times per day, according to the American Heart Association Trusted Source. Your heart beats, pushing blood against the walls of your arteries.

Now, Blood pressure (BP) is the force exerted by moving blood against blood vessel walls. So the heart's action of pumping blood through the circulatory system is mostly responsible for this pressure. Also, the pressure in the major arteries is meant when the word "blood pressure" is used without a qualifier. Moreover, systolic pressure, or the highest pressure during one heartbeat, is typically stated as the ratio of diastolic pressure, or the lowest pressure between two heartbeats, in blood pressure measurements. It is expressed as a millimeter of mercury (mmHg) above the air pressure in the immediate vicinity.

Historically, a healthcare professional would use an aneroid gauge or a mercury-tube sphygmomanometer to squeeze the artery in one arm closer to the heart while auscultating (listening) for noises in the artery. Above 115/75 mmHg, the risk of cardiovascular disease gradually rises; below this, the evidence is scant.

Observational studies show that long-term cardiovascular health is significantly improved in those whose arterial pressures are kept at the low end of these pressure ranges. The best blood pressure to target while using medications to treat hypertension, especially in older adults, is the subject of ongoing medical controversy.

Blood circulates throughout the body while the heart beats by pulsing via the arteries. It does not, however, flow continuously like a garden hose might. The pressure and pulse of the blood flow fluctuate from moment to moment. Systolic pressure is highest during a heartbeat and lowest between them (diastolic pressure). These figures are used by providers to calculate blood pressure since they are a common way to express the force of the heartbeat. It's crucial to know both your systolic and diastolic blood pressure. The measurements could indicate elevated blood pressure if they are excessively high. Your brain and other organs might not receive enough blood if the levels are too low.

Additionally, increases in the differential between the two figures are a sign that a cardiac ailment or another health issue may be present. The heart pumps blood into the arteries each time it beats. This force is measured by systolic pressure. Systole, the name for this stage, is when blood pressure is highest. When the reading of the systolic blood pressure is less than 120 mmHg (millimeters of mercury) while a person is sitting still and at rest, the blood pressure is regarded as normal. Now, when a person is exercising, under stress, or whenever their heart rate increases, their heart muscle pushes out blood with a higher pressure. Along with it, the systolic pressure increases.

Moreover, the increased pressure in these circumstances is typical. High blood pressure, on the other hand, is when the reading is elevated while the subject is at rest. It's crucial to measure your blood pressure during quiet rest intervals to successfully identify high blood pressure because your blood pressure can increase when you're active (hypertension).

The most common reason for elevated systolic blood pressure is artery constriction, which makes it more difficult for the heart to pump blood through them. However, there can be a point where the systolic pressure is too low. Hypotension is the term used when the measurement is significantly below normal. This might make you feel faint, woozy, or lightheaded. If low blood pressure is not addressed, it could lead to the kidneys and other organs starting to shut down.

Systolic hypotension might develop if your blood volume is too low. For instance, having extensive bleeding or being excessively dehydrated might both result in low blood pressure. Simply put, there isn't enough blood to move through the body in these circumstances. Additionally, low blood pressure can occur if the heart muscle is too weak to push blood correctly, such as in the case of heart muscle disease (cardiomyopathy) or excessively widening arteries (as in vasovagal syncope, a reflex that causes fainting).

Occasionally, abrupt position changes might cause low blood pressure. When you stand up, you could feel lightheaded as gravity pushes blood toward your feet. Orthostatic hypotension is a name for this prevalent disorder.

What is Diastolic Pressure?

To replenish with blood, the heart takes a break in between beats. The term "diastole" refers to the interval between beats. The reading is taken during this pause before the subsequent heartbeat is your diastolic blood pressure. At calm repose, the normal diastolic blood pressure is under 80 mmHg.

When you are resting quietly, your diastolic blood pressure is often greater if you have high blood pressure. Dehydration or significant bleeding may cause low diastolic pressure. It might also occur if the arteries loosen up and enlarge. Your exercise level, stress level, fluid intake, and other factors affect how high and low your systolic and diastolic pressures are throughout each heartbeat.

When obtaining a blood pressure reading, you should try to minimize the impact that these additional factors may have on your results. Check your blood pressure after being able to rest peacefully for at least five minutes in a calm, warm environment for the most accurate reading. The cuff should be applied to your arm at roughly heart level while you are relaxed and holding your arms at your sides. Your bladder should be empty and your legs should not be crossed, as both of these things can interfere with your ability to read. This method of measuring blood pressure is difficult in a crowded doctor's office. You could be advised by your doctor to take your blood pressure at home.

Before identifying excessive blood pressure, many experts advise keeping track of blood pressure readings over an extended period (this can include repeating the measures at home). Additionally, you should be aware that your blood pressure will fluctuate during the day. It often peaks in the morning and declines at night. Now, your doctor may ask you to take your blood pressure more than once per day, typically once in the mornings and once in the afternoon or evening. So, seek to avoid consuming it immediately after dinner or first thing in the morning.

Instead, make an effort to read in the morning before breakfast (particularly if you drink coffee or require medication) and in the evening as you prepare for sleep (and again, before you consume medications). It's crucial to stick to your blood pressure check schedule after you've established it. If you take your blood pressure at roughly the same time each day, you'll receive the most reliable numbers and comparisons.

In older people, a diastolic blood pressure of between 90 and 60 is ideal. People start feeling uneasy once you start dropping below 60. Many elderly people with low diastolic blood pressure experience fatigue or dizziness and frequently fall. Naturally, none of it is good news for the elderly, who may have fragile bones and other problems.

During the diastolic period, your coronary arteries receive nourishment. Low coronary artery pressure is a sign of low diastolic pressure, which implies your heart will be depleted of blood and oxygen. This is known as ischemia, and it is this form of persistent, low-level ischemia that has the potential to weaken the heart over time and result in heart failure.

Certain medications, notably a family of drugs known as alpha blockers, or central acting anti-hypertensive agents, are responsible for decreasing your diastolic blood pressure more than your systolic. Age is still another factor. Your vessels develop a little stiffer as you age, which tends to increase your systolic pressure and decrease your diastolic pressure. Finding ways to keep your vessels elastic, or, if they've lost it, perhaps ways to regain it, is one prospective therapy for slowing down the ageing process.

Now, currently, cutting back on salt consumption is the best course of action because it has been found to be strongly related to how elastic your blood vessels are. Also, your blood vessels will become less elastic as you consume more salt. Moreover, most people consume too much salt. Although the question of salt consumption is hotly contested in medicine, most experts agree that daily salt intakes of more than 4 grammes and less than 1.5 grammes are both excessive. Now, this varies depending on a person's age and underlying health issues, but this range serves as a decent generalization. Although this is also hotly contested, some research suggests that 3.6 grammes of salt are the recommended daily amount for healthy individuals.

Now, Dietary and exercise modifications to one's lifestyle can have instant results. Also, much more quickly than the mirror can reflect, your interior changes. So, by improving your diet, engaging in regular exercise, managing your weight, and quitting smoking, you're becoming a lot healthier on the inside.

Now, everyone believes they will need to continue doing this for six to twelve months before noticing any changes. That is untrue. The body moves around a lot. Moreover, you can start to reap the rewards of a lifestyle modification after a few weeks. You can see a difference with dietary modifications in salt intake in a day or two.

Main Differences Between Systolic Pressure and Diastolic Pressure In Points

Now, let’s look at the main differences between diastolic pressure and diastolic pressure in a bit brief by the following points:

  • Now, the systolic blood pressure reading on a sphygmomanometer is the highest number (i.e. instrument used for measuring blood pressure). The lowest measurement is diastolic blood pressure.
  • Now, the force with which the heart contracts and pushes blood from the chambers into the arteries is measured by the systolic blood pressure. The force of blood pushing against artery walls as the heart relaxes is measured by diastolic blood pressure.
  • In typical situations, systolic blood pressure is more significant than diastolic blood pressure because it predicts the risk of heart attack or stroke.
  • A normal value for systolic blood pressure should fall between 90 and less than 120. A typical value for diastolic blood pressure should fall between 60 and 80.
  • Age causes an increase in systolic pressure. Age causes a drop in diastolic pressure.
  • Systolic pressure may fluctuate frequently. There will be fewer changes in diastolic pressure.


Now, to conclude, both systolic and diastolic blood pressure are seen as crucial. A result that is very high or low could be a sign of hypertension or inadequate blood flow to vital organs. Also, depending on the condition of the heart, the level of stress, and other factors, the Systolic blood pressure and Diastolic blood pressure may change significantly from time to time.


  • Blood pressure. (n.d.). Retrieved from WIKIPEDIA: https://en.wikipedia.org/wiki/Blood_pressure
  • Fogoros, R. N. (2022, July 08). Systolic vs. Diastolic Blood Pressure. Retrieved from verywellhealth: https://www.verywellhealth.com/systolic-and-diastolic-blood-pressure-1746075
  • Windsor, M. (2015, May 17). Diastolic blood pressure: How low is too low? Retrieved from UAB News: https://www.uab.edu/news/research/item/10393-diastolic-blood-pressure-how-low-is-too-low


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"Difference Between Systolic and Diastolic." Diffzy.com, 2023. Mon. 27 Mar. 2023. <https://www.diffzy.com/article/difference-between-systolic-and-diastolic-835>.

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