The answer to 'P-trap overflowing' is that a clogged or malfunctioning P-trap is the most common cause. The P-trap is the curved pipe under your sink that is designed to hold water and prevent sewer gases from entering your home. If the P-trap becomes blocked, it can cause water to back up and overflow from the sink drain.
Some common causes of a clogged P-trap include accumulated debris, hair, or food particles. Improper installation or a damaged P-trap can also lead to overflowing. Symptoms include water pooling around the sink, foul odors, and slow draining.