Electronic home blood pressure units are the preferred machines to purchase because:
There are many manufacturers and models, but simply put, you can purchase an electronic unit with one of two options–fully automatic or semiautomatic.
The fully automatic electronic units are simple to use–they will inflate the blood pressure cuff and measure and display the blood pressure at the push of a button. They cost approximately $64-$78.
The semiautomatic electronic units are equally effective; however, they require you to pump up the blood pressure cuff yourself, with the machine measuring and displaying the blood pressure. These units cost approximately $30-$35.
The two major manufacturers of blood pressure units sold in the United States are Omron and A&D. There are other models sold (Lumiscope, Sunbeam, SunMark, and Walgrens); however, these are made by other companies and sold under different names and model numbers.
It is better to purchase from one of the major manufacturers such as Omron or A&D. These manufacturers must prove to the FDA that their products are accurate and reliable before the products can be sold in the U.S.
Only upper-arm monitors should be purchased. The wrist and finger units, although easy to use, are not reliable for monitoring blood pressure.
A properly sized cuff is very important for accurate measurements. Purchasing a cuff that is too small for your arm will result in falsely elevated readings. It is better to purchase a slightly larger cuff rather than one that is too small. If you have a large upper arm, purchase a large blood pressure cuff. Omron and A&D both offer larger cuffs for their machines; however, they may need to be purchased directly from the manufacturer.
Blood pressure measurements consist of two numbers: the first (higher) number is called the systolic blood pressure, and the second (lower) number is the diastolic blood pressure. The pulse is also recorded by all of the electronic machines. An example of a blood pressure measurement is 140/80 mmHg, which translates to 140 for systolic blood pressure and 80 for diastolic blood pressure, measured in millimeters of mercury. A normal office blood pressure is less than 135/85, with a pulse usually of 60–80 beats per minute (bpm) while the person is at rest.
Blood pressure is very variable, which means it can change for a number of reasons. Many factors can increase blood pressure; however, these elevated readings may not be significant to health. Blood pressure is elevated when a person is in pain or is upset, immediately after exercise (even walking), while talking, after tobacco usage, and immediately after caffeine usage. Elevation of blood pressure during these circumstances does not predict future harm (although there are other dangers from tobacco usage).
Blood pressure tends to be lower in the evening and lowest during sleep. Blood pressure may vary by 50–70 mmHg for systolic and 20 mmHg diastolic, depending on how it is measured. So, if you measure your blood pressure while talking, immediately after smoking a cigarette and walking back into the house, while you are upset, or in the early morning, your measured blood pressure could be 190/100. The blood pressure when repeated under the proper conditions could be 120/80. The difference is not the fault of the machine, but rather an error in the method of measurement.
The correct measurement technique is outlined below:
We know that measuring your blood pressure at home will result in lower readings than measuring it in your doctor's office. This is because you are more relaxed at home. Your home blood pressure ideally should be less than 135/85, unless you are a diabetic or have kidney disease. Patients who have hypertension and diabetes and/or kidney disease should have the office-measured blood pressure lowered to less than 135/80. You should ask your doctor what your target blood pressure should be.