Why did Egyptians give the name 'First Illness" to the years around 2100 B. C.?

The "first illness" took place around 2100 B. C. and was where the Egyptians were in very bad shape. The harvests were not plentiful, and this in itself lead to numerous diseases, malnourishment, and even starvation. Along with this, wars and anarchy broke out, as people were not happy with the government. All of this combined lead to a lot of deaths. There was also a "second illness", which was sort of the same thing, along with civil war breaking out.