Pressure Changes and Hidden Leaks
A significant leak can affect household pressure, although many other plumbing problems can do the same thing. Rural homes may also notice the well pump starting more frequently because the system keeps losing pressure.
Those symptoms do not confirm a leak on their own, but they are useful clues when combined with visible moisture or water sounds inside a wall.
Frozen Water Lines
Winter adds another concern because a frozen line can crack without leaking immediately. Once thawing begins, the damaged section becomes pressurized again and the leak can appear quickly.
If a line froze recently, inspect surrounding areas after water service returns rather than assuming everything is fine simply because the faucet works again.