In the Star Trek universe: There is a screen (pictured right) hanging above each bed in sickbay displaying various vital signs. So, no matter if you've just hit your head on a console when the ship was rocked by a photon torpedo, or if you've just wrestled with the Gorn on a desert planet, McCoy will not let you leave sickbay until those needles fall within acceptable parameters.
In real life: Hoana Medical, based in Honolulu, markets a bed coverlet hooked up to a wall monitor (pictured right). It measures heartbeat, respiration and other vital signs, and notifies hospital nursing staff if something goes wrong. You can see the LifeBed in action on this video, where a chief nurse says it's not just about the technology, but about keeping the nurses informed. However, if it were, say, Nurse Chapel taking care of Spock, there would be no question that the patient's every movement will be well-monitored, with or without the machine.