Common issues include a running toilet (caused by a faulty flapper or fill valve) and a clogged toilet (caused by flushing non-degradable items or excessive toilet paper). Leaks at the base are usually due to a damaged wax ring seal, which requires replacement.

Without a specific description, the most likely issues are a constant 'running' sound (flapper/fill valve issue) or slow drainage/clogging (blockage in the pipe). Check the water level in the tank and look for pooling water around the base to narrow down the cause.

Leaving issues like a running toilet causes significant water wastage, leading to higher utility bills over time. Leaks (especially from the base) can cause major water damage to your flooring and subfloor, requiring expensive structural repairs. Persistent clogs can indicate a larger problem like tree root intrusion that must be professionally addressed.