kare wa byouki de gakkou o yasunde imasu.

He is absent from school because of illness.

byouki no toki wa, muri o shinaide yasunde kudasai.

When you are sick, please rest and don't overdo it.

sofu no byouki ga yokunatte anshin shimashita.

I was relieved that my grandfather's illness got better.

hayaku byouki o naosu tame ni, kusuri o nomimasu.

I take medicine in order to cure my illness quickly.

kanojo wa ookina byouki o shita koto ga arimasu.

She has had a serious illness before.

saikin, byouki ni naru hito ga fuete imasu.

Recently, the number of people getting sick is increasing.