Home / Glossary / White coat effect
Conditions

White-coat effect

A temporary rise in BP at a medical facility due to stress

White-coat effect — a monitor with an inflated reading in the doctor’s office

The white-coat effect is a rise in blood pressure in the doctor’s office due to anxiety, whereas in the calm setting of home it is lower. The phenomenon is named after the traditional white coat of medical staff.

It is important to distinguish it from true hypertension and from the mirror situation — masked hypertension.

What it is

At the sight of a doctor and a medical setting, some people have a stress reaction: pressure at the appointment turns out higher than the real value. If office pressure is consistently elevated while it is normal outside the clinic and the person receives no treatment, this is called “white-coat hypertension.” The term “white-coat effect” is broader and describes the very difference between office and home pressure, including in patients already on treatment.

Why it matters

Because of this effect, hypertension can be diagnosed by mistake and unnecessary drugs prescribed, going only by the numbers in the office. On the other hand, white-coat hypertension is not always harmless: in some people it progresses over time to sustained hypertension, so such patients are followed up.

How to tell it from true hypertension

The key is measuring blood pressure outside the clinic: a home monitor by the rules (morning and evening over several days) and 24-hour monitoring (ABPM). If pressure is normal outside the office, a diagnosis of hypertension is most likely ruled out, but follow-up is kept. A calm setting at the appointment also helps: 5 minutes of rest, quiet, several measurements.

Calculate using this marker

Calculators where White coat effect is used directly:

Hypertension Risk Your blood pressure category by ACC/AHA, age- and sex-based norms, guidance, and impact on biological age Open Blood Pressure Categories Your ACC/AHA category, pulse and mean arterial pressure, risk score, and age-based norms Open

Frequently asked questions

Is the white-coat effect dangerous?

A rise in pressure from anxiety is not itself a disease. But white-coat hypertension is not always harmless: in some people it progresses to sustained hypertension. So such patients are advised to monitor pressure at home and have periodic follow-up.

How to measure blood pressure without the white-coat effect?

Measure at home in a calm setting: sit for 5 minutes, do not talk, rest against the chair back, keep the arm at heart level, take 2–3 readings. The most objective picture is given by 24-hour blood-pressure monitoring (ABPM).

Related terms

Blood pressure (BP) The pressure of blood on the artery walls, given as two values: SBP/DBP Arterial hypertension A sustained rise in blood pressure ≥130/80 mmHg — the leading modifiable risk factor for stroke and heart attack. Masked (hidden) hypertension Normal blood pressure in the clinic but elevated outside it Systolic blood pressure The upper number in a blood-pressure reading — the pressure at the moment the heart contracts. Normal: 90–119 mmHg. Resting heart rate The heart rate in a calm state CVD Cardiovascular disease

Sources

  1. 2017 ACC/AHA Guideline for High Blood Pressure in Adults
  2. American Heart Association — Understanding Blood Pressure Readings
info
This content is educational and does not replace consultation with a physician. Reference ranges may vary depending on the laboratory and method — rely on the ranges stated on your own test report.
← All glossary terms