Bathrooms have so many different running water appliances that it is common for you to have leaks from time to time. IF your bathroom is upstairs, you may first become aware of a leak when water starts to run through the ceiling of the room below. This can not only be worrying but also dangerous if it happens where electrical appliances are.
If the leak happens when you are using water in the bathroom or just after then turn it off and investigate what the issue is. If it starts leaking and no water is being used then it must be a pipe which carries the water in which case you will need to turn the water off at the stop tap.
Leaks can occur for many reasons but a common one is when a bath or sink has not been sealed properly so water runs down the side. This can then creep through the floor boards and through the ceiling below.
If your toilet has sprung a leak you need to find out if it is clean water or soiled water that is leaking. If it is spoiled water then you will also need to ensure that you give the bathroom a really good clean and will probably need to change the flooring – if not the floor boards too.