When is the "Konjuktiv 1" used?

The Konjunktiv 1 is used when: Someone wishes to distance themselves from what is being said . For example when someone is quoting someone else " er sagte,dass sie eine schwere Krankheit habe". "Habe" is the 3rd person form of haben in the konjunktiv 1 which is  necesary here in order to show that speech is being reported by someone else (to show that they are quoting someone else".