A modular patient monitor comprising: a patient monitor in communication with a first display (300; 856; 1511; 1611; 1705; 1802; 2005) and a docking base, the patient monitor, the first display (300; 856; 1511; 1611; 1705; 1802; 2005), and the docking base configured to provide patient monitoring functionality with respect to a first set of physiological parameters; and a handheld monitor (200; 602; 810; 1200; 1410; 1590; 1690; 1740; 1920; 1925) configured to communicate with the patient monitor via the docking base, the handheld monitor (200; 602; 810; 1200; 1410; 1590; 1690; 1740; 1920; 1925) having a second display (210; 1591; 1691; 2015), the handheld monitor (200; 602; 810; 1200; 1410; 1590; 1690; 1740; 1920; 1925) configured to provide patient monitoring functionality with respect to a second set of physiological parameters; wherein when the handheld monitor (200; 602; 810; 1200; 1410; 1590; 1690; 1740; 1920; 1925) is in communication with the patient monitor, the first display (300; 856; 1511; 1611; 1705; 1802; 2005) and the second display (210; 1591; 1691; 2015) are visible simultaneously, the first display (300; 856; 1511; 1611; 1705; 1802; 2005) and the second display (210; 1591; 1691; 2015) displaying at least some measurements of the first set of parameters and at least some measurements of the second set of parameters, wherein the at least some measurements comprise at least one of a waveform and a numerical value; characterized in that a user can select which measurements of either or both of the first set of parameters and the second set of parameters are displayed on or spanned across the first display (300; 856; 1511; 1611; 1705; 1802; 2005) and the second display (210; 1591; 1691; 2015). a patient monitor in communication with a first display (300; 856; 1511; 1611; 1705; 1802; 2005) and a docking base, the patient monitor, the first display (300; 856; 1511; 1611; 1705; 1802; 2005), and the docking base configured to provide patient monitoring functionality with respect to a first set of physiological parameters; and a handheld monitor (200; 602; 810; 1200; 1410; 1590; 1690; 1740; 1920; 1925) configured to communicate with the patient monitor via the docking base, the handheld monitor (200; 602; 810; 1200; 1410; 1590; 1690; 1740; 1920; 1925) having a second display (210; 1591; 1691; 2015), the handheld monitor (200; 602; 810; 1200; 1410; 1590; 1690; 1740; 1920; 1925) configured to provide patient monitoring functionality with respect to a second set of physiological parameters; wherein when the handheld monitor (200; 602; 810; 1200; 1410; 1590; 1690; 1740; 1920; 1925) is in communication with the patient monitor, the first display (300; 856; 1511; 1611; 1705; 1802; 2005) and the second display (210; 1591; 1691; 2015) are visible simultaneously, the first display (300; 856; 1511; 1611; 1705; 1802; 2005) and the second display (210; 1591; 1691; 2015) displaying at least some measurements of the first set of parameters and at least some measurements of the second set of parameters, wherein the at least some measurements comprise at least one of a waveform and a numerical value; characterized in that a user can select which measurements of either or both of the first set of parameters and the second set of parameters are displayed on or spanned across the first display (300; 856; 1511; 1611; 1705; 1802; 2005) and the second display (210; 1591; 1691; 2015).