INTRODUCTION At the initial office visit, blood pressure should be measured in both arms, ideally with electronic devices that can measure them simultaneously. SBP difference between arms >10 mmHg must be confirmed by repeated measurements. If confirmed, the arm with the higher blood pressure should be used for all subsequent measurements, as its values more accurately reflect the level of blood pressure in the major arteries. Using blood pressure readings on the arm with higher pressure improves outcome prediction. A consistent difference in SBP between the arms >15 to 20 mmHg may be due to atherosclerosis and restriction of the large intrathoracic or supraclavicular arteries, necessitating investigation of arterial disease. The blood pressure values on the right and left brachialis arteries differ in most cases, and the higher one is taken as more accurate. Prognostic significance: for each 10 mmHg difference according to Agarwal (2008), the relative risk of total mortality increases by 24%. In order to accurately assess the degree of hypertension, the spontaneous variability of pressure as a function of time and the pressure difference between the arms must be taken into account. WORK OBJECTIVES: 1. Analysis of spontaneous blood pressure variability upon arrival and repeated after 5 to 30 minutes; 2. Blood pressure differences between the left (LR) and right arm (DR). MATERIALS AND METHODS: A prospective study was conducted from the database of the "Dr. Bastać" Internal Medicine Practice on 26 patients, average age 58±12 years, with newly discovered hypertension by measuring blood pressure with the indirect manometer method at the first examination immediately after arrival and after 15 minutes. The control group consists of 28 patients who do not have hypertension. The data were statistically processed with the Student's T test. WORK RESULTS The mean value (Xsr) of systolic and diastolic blood pressure (SKP/DKP) of the examined group on arrival is 166/92 mmHg on the right hand (DR), and 161/93 mmHg on the left hand (LR). and after rest at DR 153/90 mmHg and LR 149/87. There is a statistically highly significant difference especially between the CAP on the hands - it is always higher on the right hand by an average of 5 mmHg (p=0.002) and 4 mmHg after rest. Spontaneous variability was determined in 10 (40%) subjects where there was a statistically significant drop in tension after rest. After a 15-minute rest, the significance of pressure differences between arms is maintained, but the high variability of 40% post-rest pressure variability is lost. CONCLUSION: Pressure on arrival in newly diagnosed untreated patients is always higher on the right arm by an average of 5 mmHg (p=0.002), and after rest 4 mmHg, this difference is maintained. Spontaneous variability was determined in 10 (40%) subjects where there was a statistically significant drop in tension after rest. After 15 minutes of rest, the significance of the pressure differences between the arms is maintained, but the high pressure variability is lost.