Answers:
Major disease category include cancer, musculoskeletal, cardiovascular, urogenital, respiratory, infectious, metabolic and gastrointestinal diseases.
If it is going on for anatomy, it could be :
cardiovascular, visceral, neuroanatomy, musculoskeletal.
Or muscular; vaskular,neuro & lymph; bone, visceral.
Or come first, thorax, tummy, extremities.
Or kinesiology etc.
Or you better ask your teavher to find out.
It depends on which disease you are speaking of, Each disease is different
How nearly: mild, moderate, fruitless, and Oh My God I'm Gonna Die!
take a look at the cat cubicle of the site below if it is decipherable afterwards i.e. it GL
Actually more than 4 such as: neoplasma/ malignancy, infection, trauma, intoxication, corpus alienum, degenerative, congenital, heritable, immunologic, psychosomatic, and idiopathic