What exactly happens when my doctor or nurse takes my blood pressure?

What exactly happens when my doctor or nurse takes my blood pressure?

Taking your blood pressure is an easy and painless procedure, it is also a rather speedy process and one that is conducted by most healthcare professionals as part of routine examinations. Basically, your doctor or nurse measures your blood pressure with an inflatable cuff (sphygmomanometer) that is attached to a small gauge, the cuff wraps around your upper arm. Then, the doctor or nurse will use a stethoscope (an acoustic medical device used for listening to bodily sounds) to listen to your blood moving in your artery. 

Then, your health care professional will inflate the cuff on your arm to raise it to a higher pressure than your systolic pressure (i.e. it will stop blood flow). As the cuff tightens around your arm it might be a bit uncomfortable, don’t worry, it won't hurt you and doesn’t inflate for long and it certainly won't pop from the pressure. The cuff is made from a strong and durable fabric to ensure such accidents don’t happen.

Listening to the stethoscope, your doctor will then deflate the cuff and the first sound they hear will be your systolic blood pressure when the blood is allowed to pass through the now open artery. This makes a whooshing sound, like water flowing through a hosepipe. When this sound stops, this point will mark your diastolic pressure - the artery is completely open at this point. Basically, this is when the heart has a breather, gets oxygen and isn’t pumping blood through the arteries.

That is why the systolic number always comes before the diastolic one in the blood pressure reading.

There are a number of factors that influence a blood pressure reading, but basically, the more blood that is pumped through the arteries, the higher the blood pressure. If the artery walls are stiff or narrow due to artherosclerosis (a build-up of cholesterol and fatty deposits within the arteries) they may resist the flow of blood and this will increase the blood pressure. When the artery walls are more flexible and open (as they are in healthy individuals), blood flows more easily and the resultant pressure is decreased, giving a lower reading.

When should I get my blood pressure checked?

  • If your blood pressure reading is normal and healthy, around 120/80, then you need only get it checked bi-annually, or when your doctor recommends.
  • When your blood pressure is bordering on a high reading (120 to 129 systolic / <80), referrred to as 'elevated blood pressure', then it is a good idea to consult with your doctor.
  • If your blood pressure reading is high (i.e. Systolic between 130 to 139 mmHg and diastolic 80 mmHg to 89 mmHG) you may need to start medication for hypertension and you should consult with a doctor regarding managing this.
  • If your blood pressure is low, also known as hypotension, this is generally when your reading is below 90/60, depending on your symptoms, you should consult with your doctor immediately. He or she will advise on the necessity for and frequency of future readings, lifestyle changes as well as possible medication for treatment.
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