There are some common culprits when it comes to obstructions and buildup in your sewer line, but not every clog is a result of the stuff that you pour down your drain. Naturally, when you dispose of waste material, it will inevitably form a kind of buildup in your sewer line.
Grease, oil, hair, and debris can all get caught in your drain and you will need to remove the obstruction accordingly. However, there are some things that are out of your control. An example of this is when there is an earthquake or flooding which can gave a major impact on your soil where your sewer line is located. This can cause the pipes to crack and possibly collapse, and you will need to repair the affected areas.
Overgrown tree roots are something that you should also keep in mind. They can potentially damage the joints within your sewer line and then grow inside of them, which will negatively impact the performance of your drainage system. Tree roots will also catch debris and waste materials which can lead to severe clogging.