In a general sense what is the difference between a disease…

In a general sense what is the difference between a disease that is a hypertrophy (such as myostatin-related muscle hypertrophy) vs a disease that is an atrophy (such as spinal muscular atrophy). (I am asking you about hypertrophy and atrophy NOT about those two specific diseases. Tell me how those words relay information about the state of the muscle) (2 sentences are plenty)