This is the 2228th most frequent German word.
erkrankung
"Erkrankung" means "illness" or "disease" in English.
Here 'Erkrankung' is used as a noun meaning 'disease' or 'illness'.
Die Erkrankung hat viele Menschen betroffen.
The disease has affected many people.
In this instance, 'Erkrankung' refers countably to an illness someone has experienced.
Nach der Erkrankung hatte sie lange Zeit, sich zu erholen.
After the disease, she had a long time to recover.
Here 'Erkrankung' is generalized to represent any conditions of illness.