How is Blood Pressure measured?
BP is reported as two numbers. The top number (systolic pressure) is the maximum pressure generated when the heart contracts. The bottom number (diastolic pressure) is the low point when the heart relaxes. The measurement unit is millimetres of mercury (mmHg).
What causes High Blood Pressure?
There is no single specific cause. High blood pressure results from a genetic defect which gets ‘switched on’—and these days increasingly at younger ages—when factors such as obesity, sedentary lifestyle, high salt intake, excessive alcohol consumption, physical or emotional stress become overwhelming. Approximately five to ten per cent adults have ‘secondary hypertension’ where high BP is due to an underlying disease entity like kidney disease, ailments of the adrenal gland or certain cardiovascular conditions.
What is Low Blood Pressure?
There are no universally accepted criteria for low BP (hypotension) like there are for high BP. In fact, low BP is generally not a disease; it is considered a variant of normal BP, not uncommonly seen in lightweight individuals whose BP remains around 90-100/60-70 mmHg without any associated symptoms. However, low BP can be worrisome in anyone with accompanying symptoms such as dizziness, palpitations, or weakness where there are no alternative explanations.