Brainlies -other than sickness and death, what impacts do pandemics & epidemics have on populations?

Other than sickness and death, the impacts of epidemics and pandemics is it reduces the population of a society.

3, many invasions from the Ottoman Turks resulted in the rapid decline of the Byzantine empire, 450 AD to 1454 AD

4 Many plagues, brought over from the Turks erupted in citys like Athens and Constantinople, killing a good chunk of the Empire's population