He is suffering from severe depression.

He was infected with anthrax.

He got decompression sickness after diving.

He always thinks he is sick because of his hypochondria.

He is suffering from peasant syndrome.

She is very short due to dwarfism.

He has a hypersensitivity to pollen.

His younger brother has mutism and doesn't speak a word in front of people.

His younger brother has mutism and cannot speak.

His grandfather is suffering from dementia.