Root canals. Kidney stones. Piriformis syndrome.
These are all ailments that are painful and no fun! Piriformis syndrome especially is a pain, in, well, the butt.
Seriously, people suffering from Piriformis syndrome have frequent and sometimes severe pain and numbness through the buttocks and down their legs. This occurs when the Piriformis muscle spasms. When this happens, it can end up also aggravating the sciatic nerve, which compounds the pain with tingling and numbness.