a person who is sick is just a person who is sick. They don't become a consumer until they consume something and for that you need someone to produce something to consume. A consumer is defined by consumption. Consumption is only possible if there is something to consume. They is only something to consume if that something is produced/created. That means that someone cannot be a consumer without the people who create whatever it is they consume.
This is pretty simple semantics. Not sure what you're struggling to understand here.