Squeaky brakes can panic a driver, as brakes are arguably the most important safety feature in automobiles. Sometimes the concern is warranted, as the brakes are going bad. Other times, however, there may be nothing wrong at all.
Some brake noise is considered normal. Different driving conditions can affect brake noise, including severe braking, dusty or sandy conditions, or even humidity. Certain high-pitched brake noise happens because the semi-metallic brake pads used on newer cars are harder. It's a safer and longer-lasting alternative to the asbestos material it replaced, but the noise can be annoying.
If your brakes are not as responsive as they should be or if the pedal "sinks" toward the floor, this could be an indication of a leak in the braking system. It could be an air leak (in the brake hose) or a brake fluid leak. One telltale sign of a brake fluid leak is the presence of a small puddle of fluid when the car is parked. Brake fluid looks similar to fresh motor oil, but with a less "slimy" texture.