What are the most common diseases that affect fish?

What are the most common diseases that affect fish?

Marc Grover (Professional Aquarist) gives expert video advice on: How do I know if my fish is sick?; Who will help my sick fish?; What are the most common diseases that affect fish? and more...

The most common diseases that fish hobbyists are going to run into, and not in any particular order but probably ranked this way, would be Ich, fin and tail rot, bloat, swim bladder disease and then pop eye or cloudy eye. Those are probably the ones you are going to see more than anything else.