Which would be a result of a malfunctioning excretory system?

Excretory system is important to the proper functioning of the body as it removes all the waste materials, which if accumulated, can be toxic for the body. For instance, high levels of urea in blood can be hazardous for cells of the body. When the excretory system does not work well, it can lead to several diseases including kidney stones, nephritis, cystitis, etc.