My Data-Backed Battle and Defeat of Hypertension
dennisforbes.ca
dennisforbes.ca
You should take it after sitting quietly and resting for about 15 minutes, or it will read too high.
You should find a blood pressure meter and matching cuff (they must match!) where the cuff is the right size for your arm. Many people use a cuff that is not the right size. Measure the circumference of your upper arm / bicept and buy a blood pressure machine to match.
The orientation of the blood pressure cuff matters.
Most people who do check their vitals at home never bother to compare their results to what the doctor gets. Their results are not repeatable, so their results are useless. I've even had to but an assistant at my PCP's office for using the wrong blood pressure cuff.