As people get older they inevitably develop health problems. Some are part of the aging process some can arise because the person becomes more sedentary, or is more prone to falls. Incontinence can be a trigger for skin breakdown issues and can be a cause for a higher incidence of UTIs.
There is also the issue of mental capacity. If your VIP is subject to a mental capacity assessment and they fail it then you’re in a bad place if you haven’t already applied for Lasting power of Attorney. I would strongly advise you to do this as soon as they are in need of more care or assistance even if they don’t need a full time carer at this stage.
Carers UK produce a useful factsheet on mental capacity: Factsheet UK9026 Guide to mental capacity
The Alzheimer’s Society in the UK also has some useful factsheets: