There are many possible causes of blocked drains, including:
1. Accumulation of grease, oil, and fat that solidify and clog drain pipes
2. Buildup of hair and soap scum in bathroom drains
3. Flushing inappropriate items like wipes, cotton balls, and feminine hygiene products down the toilet
4. Tree roots invading and growing inside the pipes
5. Debris, dirt, and other objects entering the drain and getting stuck
6. Poor installation or aging of the plumbing system
7. Heavy rainfalls, which can cause excess water to enter the drain system and overwhelm it.
