How Pseudohypertension Is Diagnosed

Pseudohypertension is an uncommon phenomenon, typically seen in elderly patients, in which the blood pressure measurement obtained with a sphygmomanometer (blood pressure cuff) is much higher than the actual blood pressure. Patients with pseudohypertension are mistakenly diagnosed as having hypertension when their blood pressure is actually normal.

Pseudohypertension is caused by the thickening of the walls of the arteries that may occur with aging. This thickening makes the arteries very stiff and difficult to compress. Because measuring blood pressure depends on measuring how much force it takes to compress an artery, having thick, difficult-to-compress arteries falsely elevates the sphygmomanometer reading.

Doctors usually suspect pseudohypertension in cases where:

• The blood pressure reading is very high over time, but the patient has no signs of organ damage or other complications. 
• Attempting to treat the measured high blood pressure causes symptoms of low blood pressure (dizziness, confusion, decreased urine output).

While a finger blood pressure meter or other similar devices may provide some useful data in cases of suspected pseudohypertension, the only way to confirm the diagnosis is by directly measuring the intraarterial blood pressure, that is, the pressure inside the blood vessel. This is done inserting a needle directly into a small artery.

Previously, a noninvasive technique called Osler's maneuver was used instead of direct intraarterial measurement. However, data has shown that this technique produces poor results, and its use today is considered inappropriate.