[FALSE POSITIVE AMBULATORY BLOOD PRESSURE MONITORING: CHALLENGES IN ACCURATE DIAGNOSIS OF MASKED UNCONTROLLED HYPERTENSION.].

Masked uncontrolled hypertension (MUCH), describes a mismatch between normal office measurements and out of range home blood pressure. Although it is often underdiagnosed, it is associated with high risk of hypertensive complications and morbidity. Ambulatory blood pressure monitoring (ABPM) is defined as the "reference standard" for diagnosing hypertension and is especially effective in cases of MUCH. Although there are many references on the advantages of ABPM, very few studies consider its limitations. To the best of our knowledge, false-positive ABPM has not previously been reported. We report a case in which a positive ABPM result obtained during a stressful situation became normal after being repeated in a non-stressful time. We, therefore, suggest implementing routine pre-test assessment of stressful situations in patients undergoing ABPM. This strategy will lead to improving the accuracy of ABPM and avoiding false-positive results.