Hypertension is a medical condition where the pressure inside the blood vessels is persistently elevated for prolonged periods causing damage not only to the inner lining of the vessels but eventually to the supplying organs. It is also accepted as a major risk factor for many other conditions and diseases such as coronary artery disease, stroke, heart failure, vision loss, Kidney diseases, and dementia, etc.  Hypertension is unfortunately prevalent around the globe in approximately 20% of the world ‘s adult population, increasing both their risk of morbidity and mortality significantly.

It can be broadly classified into two subsets; primary(essential) hypertension and secondary hypertension. Primary hypertension is the commonest type with an incidence of 90-95 % of all hypertensive cases and is a result of practicing an unhealthy lifestyle and some predisposing genetic factors. On the other hand, secondary hypertension has identifiable pathophysiology such as kidney diseases, endocrine disorders, and contraceptive pills, etc. and is found in around 5-10 % of all cases.

Hypertension rarely presents with any specific symptoms and is, therefore, usually found accidentally when vitals are evaluated for any other reasons.

How is hypertension diagnosed and measured?

The blood pressure is measured by two separate readings called the systolic and the diastolic pressures, which represent both maximum and the minimum pressure limits found within the arteries.  In healthy adults, the normal range of systolic blood pressure lies between the ranges of 100-130 millimeters of mercury(mmHg), whereas the diastolic pressures of 60-80mmHg are considered in range. The diagnosis of hypertension is made if the blood pressure of more than 130/80 or 140/90 is recorded at three or more separate occasions. A 24-hour ambulatory blood pressure monitoring also provides a reliable diagnosis for hypertension.

What is the white coat effect?

Measuring blood pressure cannot always provide accurate readings when carried out in a physician’s clinic. This can be explained as the white coat effect where the patient’s anxiety can result in elevated blood pressure readings when recorded in clinical settings in comparison to readings measured at home. 10-20 % of all hypertensive patients suffer from the white coat effect and generally do not require any antihypertensive medications.

Therefore, the American Heart Association (AHA) recommend regular monitoring of blood pressure at home in suspected and confirmed hypertensive patients to rule out white coat hypertension, and to monitor patients on antihypertensive therapy.

How can blood pressure be monitored at home?

Blood pressures can easily be monitored at home either by the individual or with the help of a medical or nonmedical caretaker. The patient can either employ the assistance of a manual or a digital blood monitoring device for this purpose.

Manual monitoring devices:

The manual sphygmomanometer consists of a gauge that can either be a mercury-filled calibrated tube or a calibrated dial with a pointer, attached to an inflatable cuff. The cuff is secured around the arm and is then inflated until the reading on the dial or mercury-filled tube exceeds 30-40 mmHg of the patient’s last recorded systolic pressure. The cuff is then slowly deflated with a stethoscope placed on the radial pulse inside the elbow on the same arm until the pulse is audible in the stethoscope. This marks the first reading i.e. systolic blood pressure. The deflation is again continued until the pulse disappears from the stethoscope, marking the second reading i.e. the diastolic pressure.

The advantage of using a manual monitor over their digital counterparts lies in its accuracy in reading and lower cost. Some manual monitors even have a built-in stethoscope that eliminates the need for any assistance from others.

Digital monitoring devices:

Digital monitors are now more popular among patients to monitor blood pressure as they are easier to operate. They are all in one-unit devices that give specific digital readings on small screens when turned on. They are practical solutions for individuals with hearing impairment or with limited secondary help or assistance. However, the drawbacks to digital monitors include their fluctuations in body temperature, site of placements, or if there are any pulse irregularities (eg: atrial fibrillations) along with their expensive costs.

General instructions for blood pressure monitoring:

• It should always be ensured that the patient receives proper training on how to operate their selected blood pressure monitoring device or seeks the help of a health care assistance regularly that can accurately take their blood pressure readings for them.
• It is ideal if a 30 minutes’ break is given after food to monitor blood pressure. No stimulating substances such as caffeine, alcohol, or tobacco should be consumed shortly before taking the readings.
• 3-5 minutes of rest should be given to the patient if he/she takes a reading after walking or exercising.
• The ideal position to take a blood pressure reading for the individual is to be seated comfortably in a relaxed environment with their arms outstretched and supported with uncrossed legs. The bladder should be emptied at least 5 minutes before the monitoring.
• An appropriate size of arm cuff should be used; as too tight or too loose cuffs can result in inaccurate readings.
• The arm cuff should be placed on the left arm, 1 cm above the crease of the elbow, as the left side receives direct supply from the heart and gives the most accurate readings.
• The arm cuff should always be placed on bare skin rather than over any clothing.
• Radial or brachial pulses should be palpated beforehand for any irregularities if using a digital monitoring device. If any pulse irregularities are found it is recommended to measure blood pressure manually.
• A healthcare provider should always ensure the devices employed by the individual are calibrated and work properly to prevent false readings.
• A thorough record or log should be maintained every time the blood pressure is recorded, to facilitate the effective monitoring of therapy. It is essential to take readings at the same time of the day regularly for a more accurate comparison.
• If unusually high or low readings are recorded, the readings should be repeated multiple times within a span of the next few minutes. If persistent abnormal readings are observed a health care provider should immediately be consulted.

How to understand blood pressure readings?

The normal ideal baseline for healthy individuals is the pressure of 120/80 mmHg. A diagnosis of hypertension, however, can only be confirmed by a medical professional.

• The patients understand after maintaining a log that the blood pressure values generally fluctuate over time and that no single reading can give definitive clue for diagnosis or any emergency.
• Patients are advised not to stop ar alter any hypertensive medications unless advised by their physicians even if normal blood pressure is observed on monitoring.
• A single high or low reading should not cause an alarm unless multiple reading following it show similar values.
• If two consecutive blood pressure readings cross over 180/120mmHg, medical help should be sought after immediately as the individual might be suffering from a hypertensive crisis.
• If a single high reading with visible signs and symptoms of possible organ damage are observed such as chest pain, shortness of breath, or back pain, the patient should immediately report to emergency services.

Home blood pressure monitoring recommended?

Following individuals can benefit from monitoring blood pressure at home.

• Patients with diagnosed hypertension.
• Patients initiating a new anti-hypertensive treatment to determine its efficacy.
• Patients with high-risk factors for developing hypertension and its related complications.
• Pregnant women suffering from pregnancy-induced hypertension and/or preeclampsia.
• Patients experiencing white coat hypertension

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