Blood Pressure

Meaning and Definitions

Blood pressure is the pressure exerted by the circulating blood against the inner arterial walls. As a result of each heartbeat, blood keeps gushing from the heart to all other body parts, and the intensity of gushing is termed as BP. Blood pressure is essential for normal blood through each and every cell of the body. Blood pressure is influenced by variables such as the age, general wellbeing,  time of the day, any stressors faced by an individual and the presence of systemic illness that is closely linked with the cardiac system. In a normal case, the blood pressure within the arterial walls is directly linked with the rate of heartbeat, the volume of blood per beat, peripheral resistance due to obesity, and viscosity of the blood. Scientifically, blood pressure is written as a ratio between the systolic pressure and the diastolic pressure. Systolic pressure is the pressure as a result of ventricular contraction and the diastolic is the result of atrial relaxation. During the contraction( systole), blood is ejected out of ventricles whereas the diastole will allow atrial refilling. A healthy adult has a BP ranging from  100/60 -140/90 mm of Hg. The normal BP is about  120/80 mm Hg. However, if the blood pressure rise beyoned 150/100 mm of Hg, it is called hypertension and if the pressure drops below  100/60nn Hg, it is termed as hypotension. Blood pressure is essentially one of the important biological phenomenon help to maintain the internal balance within our body, however, rapid fluctuation of blood pressure is risky. Blood pressure and heart rate are inversely proportional to each other because of a rise in the heart rate reduces the blood pressure and vice-versa. The rate, rhythm, volume and nature of heartbeat vary between different age-groups, in other words, as the person grows, BP will increase.  The following table depicts how heart rate and BP vary between different age-groups. 


Table Of Contents

  1. Meaning and Definitions
  2. Blood Pressure and the heart rate
  3. Measuring blood pressure
  4. What determines the blood pressure?
  5. Causes of increased blood pressure (hypertension
  6. Causes of decreased blood pressure (hypotension)


Blood Pressure and the heart rate


Normal BP

Normal heart rate (bpm)

From birth  to 11 months

90/60 mm hg

80 to 160

From 1 to 2 years

100/70 mm Hg

80 to 130

From 3 to 4 years

100/80 mm Hg

80 to 120

From 5 to 6 years

110/80 mm Hg

75 to 115

From 7 to 9 years

120/80 mm Hg

70 to 110

Over 10 years

120/80 mm Hg

60 to 100



Measuring blood pressure


A number of devices are being used to measure the blood pressure, but the most widely used equipment is the sphygmomanometer. A sphygmomanometer has a monometer that shows reading from 0 to 300. The BP cuffs are used to inflate while it is applied over the upper arm and they must be completely deflated or emptied before use. The patient must be in a stable condition while measuring blood pressure because this will ensure the correct reading. Ideal position used is by making the patient sit with support or make him lie flat on the bed. As a rule of hemodynamics, the monometer should be held at the level of the patient`s heart. The patient should be given an explanation of the procedure to avoid unnecessary fear and anxiety ( anxiety might result in more BP ). On inflation of the cuffs, the patient feels pressure, and the monometer must touch the levels of  150 or more and the person feels pressure in the upper arm. The knob must be slowly released to deflate it. As the cuffs are released, you will hear a loud heartbeat and the first beat is recorded as the systolic pressure, the last loud beat is the diastolic pressure.


What determines the blood pressure?

Blood pressure is influenced by a number of factors such as the person`s age, lifestyle, general health status, gender, body weight, cardiac health, food habits, family history of BP. It is also important to understand that the intake of stimulants such as caffeine before measuring the BP, stress levels and emotional stability can result in an increase in the reading.  In some individuals, it is pretty evident that the individual`s posture while recording the BP can result in the increase or decrease of values, this is especially true when a person assumes a standing posture. Such condition is known as the Postural (orthostatic) hypotension. Orthostatic hypertension occurs when the BP of a person drops significantly soon after the patient assumes a standing or upright posture. Patients with orthostatic hypotension may experience dizziness, lightheadedness and syncope.


Causes of increased blood pressure (hypertension)

  1. Smoking and drinking too much alcohol

  2. Being overweight or obese where the height and weight ratio is too high.

  3. Lack of physical activity or sedentary lifestyle.

  4. Intake of high spices and salt in the diet because sodium present in the salt affects the blood pressure directly.

  5. Inability to cope with stress.

  6. Age above 50 is of moderate-risk and above 60 is a high-risk factor.

  7. Genetic tendency or familial history of hypertension.


Causes of decreased blood pressure (hypotension)


  1. Pregnancy

  2. Anaemia and weakness

  3. Heart problems

  4. Endocrine disorders

  5. Severe dehydration

  6. Chronic Blood loss

  7. Severe infections

  8. Severe allergic reaction (anaphylaxis).

  9. Poor nutrition 




Course List