When you notice that your water bill is higher than you expect it to be, you probably want to figure out what the problem is. Once you make sure none of the faucets are leaking and that there isn't a mysterious water gremlin siphoning out your water, it's time to figure things out. There are a lot of ways that you can do that. The easiest way to do that is for you to get a plumber to come out and help you. They will have various tools that they can use to help you figure out where the leak is so that it can be fixed.
One way the plumber can help you figure out where the leak in your pipe lives is to send a camera down your pipes. There are small cameras that are on the end of flexible fiber optic cables. Those cables can be steered down into the pipes from various places in your plumbing system. The plumber will be able to look at the monitor so that they can see if there is any damage to the pipes and see if they can see where the leak is.
Another way that the plumber can help you figure out where the leak may be is to do a visual inspection of the area so that they can see if see it that way. The plumber will walk from the water meter up to the house, looking for mushy, soggy, or muddy spots. That would be a sign that there is a leak in that particular area. The plumber will also look around at all the walls and ceilings to see if they can figure out where the leak is. That can be more difficult because water tends to flow so the leak may be somewhere that is distant from where the evidence shows up.
The plumber may also introduce some dye into your water supply so that when it hits the leak, it will show up. The more intense the color, the worse the leak. You may worry about it staining your walls or ceiling, but there is a good chance that the wall or ceiling or floor would have to be replaced in order to get access to the pipe to fix it anyway, so that shouldn't be a worry.
If you have think that you have a leak, you should call plumbing contractors and have them check it out for you.