Sedation can be described as a decrease in a person's physical energy levels which are interpreted as discouraging when it comes to wakefulness, movement, performing tasks, talkativeness, and general exercise. At lower levels, sedation typically results in feelings of general relaxation and a loss of energy. At higher levels, however, sedation typically results in the person passing out into temporary unconsciousness. This effect is capable of manifesting itself across the 4 different levels of intensity described below:
- Minimal sedation - At the lowest level, the person will feel subtly lower in energy and alertness. They will likely have an increased desire to sleep or at least relax in a manner which is typically possible to ignore.
- Moderate sedation - At this level, the person will begin to drift off to sleep. However, they will still respond to noises and physical sensations if they are particularly prominent or above usual noise levels.
- Deep sedation - At this level, the person will have drifted off into a deep sleep. They will typically be mostly unresponsive unless subjected to repeated or painful stimulation.
- General anaesthesia - At the highest level, the person will be completely unconscious. They will be completely unarousable even with repeated painful stimulus.