A few points come to mind of my own. EJ makes a lot of sense as ever, so I am only going to add a few thoughts.
The 6th house is essentially the house of Virgo, so it is not entirely accurate to say that it is the house of health per se; it is certainly the house of nutrition, of taking care of our bodies, of taking care and giving ourselves regular good maintenance. This is where the health connotation
arises because if the 6th is afflicted then our habits are not conducive to proper good maintenance of our health. If you like it is akin to having an accident, but not suddenly, rather we have built up to it slowly and gradually by not attending to our small duties to our own wellbeing. This is the key to properly understanding the 6th, which is the espression of Virgo in outer life. Here also is the key to the 6th being the house of work; actually it is not the house of work, but rather it is the house of habituated practicality, it is what we do on a day to day basis to meet the practical requirements of life, thus it has some influence over menial work, but for the career? For money? It is too sweeping a definition to say it rules all of "work" in this way.
Actually EJ has already made some very accurate observations about my own Chiron placement, I have Chiron in the 6th, also in Pisces, and I experienced a real crisis (or three) over the last couple of years that affected my spiritual health (Pisces/6th): I became depressed, I think that is a very accurate outlet for Chiron in Pisces in the 6th. Actually I have really discovered my own compassion as a result, and feel much better placed to help others now.
That is key too; apparently, many with Chiron descending in the 6th or 7th become terapists and counsellors, either for health, nutrition and lifestyle issues if the former, and for marriage and relationships in the latter case. I can also say that until Chiron is activated by the crisis then you might not be particularly aware of it either, because it is the "wounded" healer after all, not the "unwounded" one
My feeling would be that the crisis required to kick-start Chiron themes in our lives for a 6th house placement might well be to do with illness; but illness is only a manifestation of a psychic predilection which, unresolved, eventually is forced out, into matter. My feeling is that work can be covered by an amalgam of planets and placements: Saturn for ambition, 2nd House for what we do for money and so forth; health is just the same; people with strong 6th houses are often perfectly well, and people become gravely ill even without any 6th house influence.
Jupiter in the 6th is a good example. Illness can result from overindulgence, but often that very profligacy of habit (remember the Virgo connection) is induced by an ever-expanding timetable of daily matters which must be taken care of; it is exhausting for these people who are always having to attend to the minutiae of things and the quantity of 'habits' grows with the years. It is all connected, and sublimely too.
Chiron in Leo in the 6th might speak to me of pride going before a fall; thus overconfidence or as EJ says, a creativity problem. I have seen this exact placement in the chart of someone who unable to have children because their partner was sterile eventually became a foster parent and enriched several children's lives with their givingness. That is another profound Chirotic tale.