You can find out if you have high blood pressure by having your blood pressure checked regularly. Most doctors diagnose a person with high blood pressure on the basis of two or more readings, taken on several occasions. A consistent blood pressure reading of 140/90 mmHg or higher is considered high blood pressure.
Some people experience high blood pressure only when they visit the doctor’s office. This condition is called “white-coat hypertension.” If your doctor suspects this, you may be asked to monitor your blood pressure at home or asked to wear a device called an ambulatory blood pressure monitor. This device is usually worn for 24 hours and can take blood pressure every 30 minutes. In this section you will learn more about diagnosing high blood pressure.
High blood pressure often has no signs or symptoms. The only way to find out if you have high blood pressure is to be tested for it.
A blood pressure test is quick and easy. Blood pressure is measured in millimetres of mercury (mmHg) and recorded as two numbers – the systolic pressure “over” the diastolic pressure. The systolic pressure is the first or top number, and the diastolic pressure is the second or bottom number (for example, 120/80). If your blood pressure is 120/80, you say that it is “120 over 80”.
Both numbers in a blood pressure reading are important. As we grow older, systolic blood pressure is especially important because the diastolic decreases in people aged over 55.
To test your blood pressure, your doctor will probably use a sphygmomanometer and a stethoscope.
New blood pressure testing devices use electronic instruments or digital readouts. In these cases, the blood pressure reading appears on a small screen or is signalled in beeps, and no stethoscope is used.
Here are some tips for having your blood pressure measured:
Don’t drink coffee or smoke cigarettes for at least 30 minutes before having your blood pressure measured. Before the test, sit for five minutes with your back supported and your feet flat on the ground. Rest your arm on a table at the level of your heart. Wear short sleeves so your arm is exposed. Go to the bathroom prior to the reading. A full bladder can change your blood pressure reading. Get two readings, taken at least two minutes apart, and average the results. Ask the doctor or nurse to tell you the blood pressure reading in numbers. If your blood pressure is high, go back for a repeat measurement(s) in a week’s time.
Tests at home can be done with the familiar blood pressure “cuff” and a stethoscope, or with an electronic monitor, such as a digital readout monitor. Also, be sure that the person who will use the device reads the instructions before taking blood pressure readings.
Your doctor, nurse, or pharmacist can help you check the device and teach you how to use it. You also may ask for their help in choosing the right one for you. Blood pressure devices can be bought at various places, such as discount chain stores and pharmacies and can be purchased for less than $200 US.