The invention relates to a method of operating a long-term blood pressure measurement device having a measurement sensor for detecting a pulse wave signal, having a measurement sensor for body current signals, having a pressure cuff for a non-invasive determination of the blood pressure, having a control and evaluation unit for determining blood pressure values, on the one hand from signals acquired by means of the pressure cuff (pressure cuff signals), and, on the other hand from a pulse wave transit time that is derived from body current signals and pulse wave signals, and having a memory for storing blood pressure values.