What is Blood Pressure?

Exercise, Health, Lifestyle

Blood pressure main

What is blood pressure (BP)?

Blood pressure is the pressure exerted by the circulating blood on the walls of the blood vessels.

What system is it part of and why?

BP is a part of the blood circulatory system, which is also known as the cardiovascular system(Refer Fig 1)

  • The heart
  • The blood vessels – arteries and veins
CirculatorySystem

Fig 1: The Circulatory System

The heart acts as a pump that is responsible for,

  • pumping oxygenated blood carried by the arteries to our organs
  • pumping deoxygenated blood that it receives through the veins from our organs. 

One of the functions of the circulatory system is to regulate the blood pressure for maintaining good blood flow throughout the body. This is required in order to transport nutrients and oxygen for every body part, for regulating body temperature, pH balance and for normal functioning of the body.

For example, when the heart pumps out oxygenated blood through the arteries, the blood flow exerts a force on the walls of the arteries. This force is measured as arterial blood pressure as shown in Fig 2. Any problems with this arterial BP may lead to a problem with the normal functioning of the body.

blood pressure

Fig 2: Arterial Blood pressure 

How is Arterial BP measured? 

The instrument that can measure the blood pressure is called Sphygmomanometer (Refer Fig 

Sphygmomanometer

Fig 3: Sphygmomanometer

It consists of:

  • a cuff,
  • a pump, and
  • a calibrated mercury scale

Typically two numbers that are being recorded on the scale which is written as a ratio. For example, BP of 120/70 mmHg, where 120 is the top number and 70 is the bottom number.

BP Measurement

Fig 3: Measuring BP

As shown in Fig 3, the BP is measured in four steps,

Step 1: Locate the pulse on an artery of the arm

Step 2: The health professional wraps the cuff around your arm and inflates it to squeeze your arm. This is done to temporarily press on the artery and close the blood flow in your arm. 

Step 3:  After the cuff is inflated, the health professional will slowly let air out. While doing this, he or she will listen to your pulse with a stethoscope and watch the mercury level on the calibrated scale to accurately note the measurements. The first pulse sound is heard and simultaneously measured on the scale.

Step 4: As the successive pulse sounds continue the professional hears it until the last pulse sound is heard which is again measured. 

The scale used is in “millimeters of mercury” (mmHg) to measure the pressure in your blood artery.

Blood pressure numbers- what does it indicate? 

systole and diastole

Fig 4: Systole and Diastole of the heart

The top number- Systolic pressure

The top number, which is also the higher of the two numbers, is the measure of the pressure in the arteries when the heart beats or contracts to pump the oxygenated blood. This is also known as the systole of the heart as shown in fig 4. 

The bottom number- Diastolic pressure

The bottom number is also the lower of the two numbers. It indicates the pressure in the arteries when the heart muscles are relaxing between two heart beats and refilling with blood. This is also known as the diastole of the heart as shown in fig 4.

BP Categories

Fig : BP Categories

Fig 5: BP Categories

Typically more attention is given to the top number (the systolic blood pressure), however, both the systolic and the diastolic pressures are important for indicating if a person is at risk of any heart disease.

What are the risk factors that will lead to high or low BP?

Risk factors

High BP

Low BP

  • Family history of High BP
  • Advanced age
  • Men get High BP more than women
  • Sedentary lifestyle
  • Poor diet, excessive salt intake
  • Drinking too much alcohol
  • Obesity
  • Smoking
  • Stress
  • Sleep apnea- a sleep disorder in which tissues in the throat collapse and block the airway.
  • Prolonged bed rest
  • Pregnancy
  • Trauma- loss of blood from major trauma, dehydration or severe internal bleeding
  • Certain medications
  • Abnormally low heart rate 
  • Endocrine problems- thyroid problems, Diabetes
  • Severe infection
  • Severe allergic reaction
  • Anemia
  • Nutritional deficiency- low blood volume due to Vit B12 and folic acid deficiency
  • Extreme heat- hot sauna and hot bath

When to seek Medical help?

There’s a common misconception that people will experience symptoms such as nervousness, sweating, difficulty sleeping or facial flushing. But the truth is that changes in blood pressure can be a symptomless condition. If you ignore your blood pressure because you think symptoms will alert you to the problem, you are actually taking a risk. It is important to know your blood pressure numbers as everyone should prevent blood pressure problems.

However, there are few signs and symptoms that may possibly occur with low and high BP. 

Signs and symptoms 
High BP Low BP
  • Severe headaches
  • Severe anxiety
  • Shortness of breath
  • Nosebleeds
  • Blood spots in the eyes
  • Facial flushing

 

  • Dizziness or lightheadedness
  • Fainting
  • Dehydration and unusual thirst
  • Lack of concentration
  • Blurred vision
  • Nausea
  • Cold, clammy, pale skin
  • Rapid, shallow breathing
  • Fatigue
  • Depression

 

How to manage BP problems?

Routine Check-up: Most people are unaware of their BP problems and going for a check-up will detect any blood pressure problems. This will prevent any potential health conditions. 

Understand your normal level of BP: There is no healthy level of high blood pressure or low blood pressure.  Your healthcare professional will determine your treatment goals based on your overall lifestyle and your body.

Lifestyle modifications

  • A nutritional diet, which may include reducing salt depending on High or low BP, Vitamin and mineral rich diet.  
  • Physical activity – exercise
  • Maintaining a healthy weight
  • Stress management
  • Smoking cessation support
  • Alcohol limitations
  • Prescribed medication in specific cases

Take precautions while exposed to heat 

When your body gets heated up during hot weather or during a hot tub or sauna bath, your blood pressure could drop and your heart rate may increase to counteract a drop in blood pressure. Normally, these events don’t cause problems. However, if you have an existing low BP you may be at risk of fainting, falls and heart problems.

Some of the precautions can be,

  • Limit your exposure to heat. Most experts say no more than five to 10 minutes is safe.
  • Stay hydrated.
  • Regulate water temperature during hot tub or sauna baths.

Conclusion

Managing blood pressure requires an individual’s adherence to the lifestyle changes and habits. It is advisable to get early assessment and treatment of your blood pressure problems in order to have a healthy circulatory system and to prevent the risk of many health conditions.    

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