A 57-year-old man visited his physician after his first annual health examination revealed a high systolic and diastolic blood pressure (BP) of 165/98 mm Hg. This value represented an average of 2 readings measured by a public health nurse using a validated automatic device. At the physician’s office, the patient’s BP averaged 156/90 mm Hg when readings were assessed in the clinic using the same technique. He did not have hypercholesterolemia, diabetes, obesity, smoking history, or cardiovascular complications.

To exclude the possibility of white-coat hypertension, the physician recommended that the patient purchase a device validated for BP self-measurement. The importance of detecting white-coat hypertension was explained, and the patient received instructions to measure his BP at home once every morning for 4 weeks. Measurements were to be taken within 1 hour of waking while seated and resting for more than 2 minutes, as recommended in the Japanese Society of Hypertension guidelines. The physician taught the patient to measure his BP using a self-measuring device in the office, gave him a formatted sheet on which he was asked to record all measured values, and asked him to bring the sheet with the purchased device to the physician’s office after 4 weeks.

At the 4-week follow-up visit, the physician confirmed that the device was well calibrated and that the patient was measuring his BP correctly. The 4-week average of the home BP values in the morning was 123/77 mm Hg. Thus, the physician diagnosed white-coat hypertension.

Based on current evidence, the physician explained that participants with white-coat hypertension are more likely to develop sustained hypertension and asked the patient to continue measuring his BP at home. If his BP values were greater than 135/85 mm Hg at any time, the patient was encouraged to return with the recordings and the device to the office for further evaluation.