What are Systolic and Diastolic Blood Pressures?

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Maintaining a healthy blood pressure level is crucial for heart and organ function. High or low blood pressure levels, if not managed can lead to a variety of health problems. It is necessary to learn about blood pressure to comprehend how it affects your health properly.

What is blood pressure?

Blood pressure can be defined as the pressure or force that blood exerts on the walls of arteries while passing through our circulatory system. It is an important force because, without blood pressure, oxygen and nutrients would not be pumped around our circulatory system to nourish tissues and organs.

Blood pressure is also essential for the transportation of white blood cells and antibodies for immunity, as well as hormones like insulin.

The new blood provided can pick up the toxic waste products of metabolism, such as the carbon dioxide, which we exhale with every breath, and the toxins we remove through our liver and kidneys, which is just as crucial as giving oxygen and nutrition.

How is blood pressure measured?

Blood pressure is stated as a pair of equally essential figures, such as 120/80 mmHg. The top number represents the systolic pressure, which is the amount of pressure in the arteries during heart muscle contraction. The lowest value is the diastolic pressure, which is the blood pressure while the heart muscle is resting between beats.

A normal blood pressure level/reading is less than 120/80 mmHg.

What is systolic blood pressure?

Systolic blood pressure measures the pressure in your arteries during your heartbeats. While both numbers in a blood pressure measurement are important for detecting and managing high blood pressure, doctors are most concerned with the top number, often known as systolic pressure.

Over time, studies have revealed that both figures are equally significant in monitoring heart health. However, most studies suggest that higher systolic pressures are associated with a higher risk of stroke and heart disease than raised diastolic pressures. This is especially true in adults over the age of 50, so doctors pay more attention to the top number. The difference in risk levels may be due to the stress exerted on the arteries when blood rushes out of the heart.

What is diastolic blood pressure?

Diastolic blood pressure measures the pressure in your arteries when your heart rests between beats or the pressure when the vessels relax between your heartbeats. Low diastolic blood pressure can cause heart damage and raise your risk of heart disease.

Blood pressure categories/stages

Blood pressure measurements are classified into four groups, ranging from normal to high blood pressure (Hypertension).

Blood pressure stagesSystolic (mm Hg)Diastolic (mm Hg)
NormalLess than 120Less than 80
Elevated120-129Less than 80
Stage 1 – Hypertension


High Blood Pressure

Stage 2 – Hypertension


High Blood Pressure

140 or higher90 or higher
Hypertension CrisisHigher than 180Higher than 120

How is blood pressure measured?

A sphygmomanometer is used to measure blood pressure. It comprises a rubber wristband – the cuff – that is inflated by hand or machine pump.

Once the cuff has been inflated sufficiently to halt the pulse, a reading is obtained, either electronically or on an analogue metre.

The reading is given in terms of the amount of pressure required to drive mercury along a tube against gravity. This explains why pressure is measured in millimetres of mercury, shortened as mm Hg.

Risk of high blood pressure (Hypertension)

High blood pressure or Hypertension adds more pressure on your blood vessels, heart and other organs such as the brain, kidneys and eyes.

Persistently high blood pressure can raise your risk of a variety of severe and sometimes fatal health issues, including:

If you have high blood pressure, even a little reduction can significantly lessen your risk of certain health problems.

Risk of low blood pressure (Hypotension)

Low blood pressure condition occurs when blood pressure drops below the normal range. This life-threatening condition can occur as a result of severe Hypotension. Some early signs include confusion, especially in old-aged people. Other symptoms include:

  • Dizziness or lightheadedness
  • Nausea
  • Blurred vision
  • Cold, clammy and pallid skin
  • Breathing is quick and shallow.
  • The pulse is weak and fast.

In Conclusion

Your blood pressure level dictates the type of treatment you may require. To obtain an accurate blood pressure reading, your doctor should average two or more blood pressure measurements taken during three or more visits.

According to the American Heart Association, high blood pressure is currently defined as 130/80 mm Hg or greater. This will significantly improve the survivability of thousands of patients who need to monitor and regulate their blood pressure.

While recording blood pressure measurements is a vital task that should be repeated for consistency and confirmation, not all cases of high blood pressure will require medical treatment. The new recommendations urge that you check your blood pressure frequently, preferably with a home monitor, to assist your doctor in determining if you need to make lifestyle changes, start medication or change your treatment.


The Information including but not limited to text, graphics, images and other material contained on this blog are intended for education and awareness only. No material on this blog is intended to be a substitute for professional medical help including diagnosis or treatment. It is always advisable to consult medical professional before relying on the content. Neither the Author nor Star Health and Allied Insurance Co. Ltd accepts any responsibility for any potential risk to any visitor/reader.

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