WISH UR HEALTH: BLOOD PRESSURE ( B P )

1. Introduction :--

Blood pressure (BP) is the pressure of circulating blood on the walls of blood vessels. Most of this pressure is due to work done by the heart by pumping blood through the circulatory system. Used without further specification, "blood pressure" usually refers to the pressure in large arteries of the systemic circulation. Blood pressure is usually expressed in terms of the systolic pressure (maximum in between two heartbeats) over diastolic pressure (minimum in between two heartbeats) and is measured in millimeters of mercury (mmHg), above the surrounding atmospheric pressure.

It is an important force because oxygen and nutrients would not be pushed around our circulatory system to nourish tissues and organs without blood pressure. Blood pressure is also vital because it delivers white blood cells and antibodies for immunity, and hormones such as insulin. Just as important as providing oxygen and nutrients, the fresh blood that gets delivered is able to pick up the toxic waste products of metabolism, including the carbon dioxide we exhale with every breath, and the toxins we clear through our liver and kidneys.

2. Function :--

Blood flows through our body because of a difference in pressure. Our blood pressure is highest at the start of its journey from our heart - when it enters the aorta - and it is lowest at the end of its journey along progressively smaller branches of arteries. That pressure difference is what causes blood to flow around our bodies.

Arteries affect blood pressure in a similar way to the physical properties of a garden hose pipe affecting water pressure. Constricting the pipe increases pressure at the point of constriction. Without the elastic nature of the artery walls, for example, the pressure of the blood would fall away more quickly as it is pumped from the heart.

While the heart creates the maximum pressure, the properties of the arteries are just as important to maintaining it and allowing blood to flow throughout the body. The condition of the arteries affects blood pressure and flow, and narrowing of the arteries can eventually block the supply altogether, leading to dangerous conditions including stroke and heart attack.

Blood pressure fluctuates from minute to minute and normally shows a circadian rhythm over a 24-hour period, with highest readings in the early morning and evenings and lowest readings at night.

3. Measurement :--

STANDARD SPYGMOMANOMETER

Arterial pressure is most commonly measured via a sphygmomanometer, which uses the height of a column of mercury, or an aneroid gauge, to reflect the blood pressure by auscultation. It consists of a rubber armband – the cuff that is inflated by hand or machine pump. Once the cuff is inflated enough to stop the pulse, a reading is taken, either electronically or on an analogue dial.

The reading is expressed in terms of the pressure it takes to move mercury round a tube against gravity. This is the reason for pressure being measured using the unit millimeters of mercury, abbreviated to mm Hg.

4. Ranges :--

The National Institutes of Health cites normal blood pressure to be below 120 mm Hg systolic and 80 mm Hg diastolic.

However, blood pressure changes naturally is a fact that cardiologists explored while writing about blood-pressure variability in Nature in March 2013:

"Blood pressure is characterized by marked short-term fluctuations occurring within a 24-hour period (beat-to-beat, minute-to-minute, hour-to-hour, and day-to-night changes) and also by long-term fluctuations occurring over more prolonged periods of time (days, weeks, months, seasons, and even years)."

The guidelines state that for blood pressures above a figure of 115/75 mm Hg, every rise of 20/10 mm Hg doubles the risk of cardiovascular disease.

The average blood pressure for full-term infants:

· Systolic 65–95 mmHg

· Diastolic 30–60 mmHg

5. Disorders of Blood Pressure :--

Disorders of blood pressure control include high blood pressure, low blood pressure, and blood pressure that shows excessive or maladaptive fluctuation.

5.1. High blood pressure:

Hypertension or high blood pressure is a chronic medical condition in which the blood pressure in the arteries is higher than it should be. This requires the heart to work harder than normal to circulate blood through the blood vessels. Hypertension can cause many problems, including heart attack, stroke, congestive heart failure, and kidney failure. To stay healthy, most people should try to keep their blood pressure below 140/90 mmHg.

Hypertension can often be fixed with changes in diet or lifestyle:

- Lose weight if they are overweight or obese ; Exercise regularly ; Decrease the amount of salt they eat ; Limit the amount of alcohol they drink ; Eat a lot of fruits and vegetables

If lifestyle changes do not decrease a person's blood pressure, then the person may need medications. A doctor will choose which medications to use, based on what other medical problems the person has. Examples of medications that decrease blood pressure include:

- Diuretics, which increase urination to get rid of extra fluid ; Beta blockers, which slow down the heart rate ; ACE inhibitors, which relax the arteries

5.2. Low blood pressure:

Low blood pressure is known as hypotension. This is a medical concern if it causes signs or symptoms, such as dizziness, fainting, or in extreme cases, circulatory shock.

Causes of low arterial pressure include:

- Sepsis ; Hemorrhage – blood loss ; Cardiogenic shock ; Neurally mediated hypotension (or reflex syncope) ; Toxins including toxic doses of blood pressure medicine ; Hormonal abnormalities, such as Addison's disease ; Eating disorders, particularly anorexia nervosa and bulimia

If low blood pressure makes a person faint, the person could hurt themselves while falling. If a person's blood pressure is very low, the heart will be unable to pump blood and oxygen to important parts of the body. Every part of the body needs blood and oxygen to live. Without blood and oxygen, important parts of the body, like the heart and brain, can be damaged.

Doctors can treat hypotension by treating whatever is causing the low blood pressure. Sometimes, low blood pressure is caused by dehydration. This can be treated by having the patient eat more salt, drink more fluids, or (in serious cases) get fluids through a needle placed into a vein.

If low blood pressure is caused by medicines, doctors can change those medications to others that do not lower blood pressure as much. There are also medications that increase blood pressure. They work by making it harder for blood vessels to relax.

6. Blood Pressure Measuring Devices :--

6.1. Manual Sphygmomanometers :

A sphygmomanometer, also known as a blood pressure meter, blood pressure monitor, or blood pressure gauge, is a device used to measure blood pressure, composed of an inflatable cuff to collapse and then release the artery under the cuff in a controlled manner, and a mercury or mechanical manometer to measure the pressure. It is always used in conjunction with a means to determine at what pressure blood flow is just starting, and at what pressure it is unimpeded. Manual sphygmomanometers are used in conjunction with a stethoscope.

A sphygmomanometer consists of an inflatable cuff, a measuring unit (the mercury manometer, or aneroid gauge), and a mechanism for inflation which may be a manually operated bulb and valve or a pump operated electrically.

6.2. Digital Portable for Upper Arm with Automatic Inflation :