Assume that you have pain in your body and you go to a doctor for consultation, he diagnosis and tells you the probable cause. On many occasions you also go to another doctor who you normally consult and also check with him to know what might be the cause. Many people do this to feel reassured.
So, when it comes to blood pressure monitoring, why do you take just one reading and consider it to be accurate? Studies have shown that a single blood pressure reading invariably will prove to be inaccurate. Even world academic bodies have recommended to measure the blood pressure “3” time because normally the first reading of blood pressure has been found to be always on the higher side and 2nd and 3rd readings are lower than the first. Normally the average of 3 readings represents your real blood pressure at the time you measure the blood pressure.
The reason for the first blood pressure measurement being on the higher side is the patient consciously or unconsciously becomes little anxious and come under little tension. This itself momentarily increases the blood pressure. However when the blood pressure device continuous to measure the blood pressure 2nd and 3rd time the initial anxiety and the stress also comes down and effectively also reduces the blood pressure. Therefore it is important always to measure blood pressure 3 times to see the average that represents your real blood pressure.
This observation has been proven in the National Family Health Survey (NFHS-4) that conducted a nationwide survey to test the blood pressure of 1.3 million adults in India from 2015 to 2016.
The test was done to note the first reading of the systolic blood pressure (SBP) and diastolic blood pressure (DBP) of all the participants. Similarly, two more blood pressure readings were taken and the SBP & DBP readings were noted. The results showed that there was a 63% higher number of hypertension cases reported when only the first reading was considered for diagnosis compared to the average of the second and third readings. This resulted in a decrease of 3.6 mmHg and 2.4 mmHg of the average SBP and DBP readings, respectively. The experiment concluded that if only the first blood pressure reading is considered, then 16.5% of the participants were found to have hypertension. If an average of the second and third readings were considered, only 10.1% of the participants were diagnosed with hypertension. Finally, when an average of all three readings were considered, hypertension was observed in 11.0% of the cases.
This study concludes that whenever you measure the blood pressure at home, preferably use the blood pressure device which automatically measures blood pressure 3 times and gives you the average.
Recently, such devices have been made available in India.