How is blood pressure measured?
To find out your blood pressure, two measurements are recorded during a single heartbeat:
the level of pressure when your heart pumps blood through your arteries and around your body (systolic pressure): this is when the pressure is highest, and
the level of pressure when your heart is resting before it pumps again (diastolic pressure): this is when the pressure is lowest
Blood pressure is measured in millimeters of mercury (mmHg). The readings are given as two numbers or levels. The systolic reading is first, followed by the diastolic reading. For example, if you’re systolic reading is 120mmHg and your diastolic reading is 80mmHg, your blood pressure is 120 over 80. This is commonly written as 120/80.
Blood pressure can be high, normal or low.
If you consistently have a reading of 140/90 or higher, you may have high blood pressure (hypertension). High blood pressure increases your risk of developing some health conditions, including cardiovascular disease.
Generally, the lower your blood pressure, the healthier you are. As a general guide, the ideal blood pressure for a young healthy adult is 120/80 or lower. However, it’s possible to have abnormally low blood pressure.
People with a reading of around 90/60 or lower are generally considered to have low blood pressure. For some people with low blood pressure, there may be an underlying cause that could need treatment.