The invention relates to a
medical treatment device (1) comprising a stationary unit (1a) and a mobile unit (1b) that can be separated from the stationary unit (1a). The invention relates to a stationary unit (1a), which can be connected, for example, to a stationary or domestic
water source (5) and / or can be connected, for example, to a stationary or domestic water outlet (13) by means of a
discharge line (11) in order to
discharge dialysis waste liquid, and which comprises a mixing device (19), which in turn is configured to prepare and / or heat
dialysis liquid for treating a patient (P). The mobile unit (1b) is configured to treat the patient (P), in particular renal replacement treatment, where the mobile unit (1b) comprises at least one line selected from the group consisting of a
dialysis fluid input line (31) to the patient, a dialysis waste
fluid output line (32) from the patient, and a patient connection line (33) for connection to the patient, and / or comprising a connector for connecting the line to the mobile unit (1b). The stationary unit (1a) and the mobile unit (1b) each comprise a connection (27, 29) so as to be connectable in fluid communication with each other.