Whether it is appropriate to leave someone with dementia alone depends entirely on their current level of functioning and the specific risks in their environment. In the earliest stages, many people retain enough ability to manage safely for short periods. However, as the condition progresses, the potential hazards of being left alone multiply. The person may forget to turn off the cooker, leave the front door open, become lost in their own home, or fall without being able to call for help. There is no legal definition in the UK of how long someone with dementia can be left alone, but leaving a person in a situation where they are at clear risk of harm could be considered a safeguarding concern.