Simplify the following text for a Grade 14 native English-speaking person.
Original: Modern medicine , both conventional and complementary , recognizes that the different rheumatic disorders have different causes ( and several of them have multiple causes ) and require different kinds of treatment .
Simplified: Modern medicine , both conventional and complementary , shows that the different rheumatic disorders have different causes ( and several of them have more than one ) and need different kinds of treatment .