The answer to 'toilet overflowing' is that there are several common causes, including a clogged toilet, a problem with the toilet's flapper valve, or a blockage in the drain line. Symptoms may include water spilling over the toilet bowl, a gurgling sound, or the toilet taking a long time to flush.
To troubleshoot an overflowing toilet, first try plunging the toilet to clear any clogs. If that doesn't work, you may need to check the flapper valve and other internal components. In some cases, the issue could be a more serious blockage in the drain line that requires a professional plumber to address.