Hospital etiquette is a form of behavior that affects both patients and visitors. It requires some common sense but also some research to do it right. Hospital etiquette didn't have a proper name until just a few years ago, although the norms of what is acceptable in a hospital setting haven't changed much over the past half century or so.
The first rule of hospital etiquette is to be considerate of anybody who is sharing the patient's room. This means keeping noise down, not bringing an excessive amount of flowers, and avoiding perfumes or foods with strong aromas that can cause discomfort or allergies. If you are visiting with children, make sure they will behave; do not let them walk around the room, touching everything. If you can't control them, it may be better to leave them at home. The same holds true if you are sick or simply not feeling your best. A patient recuperating from a surgery should avoid contact with people who have the flu or other contagious diseases that can slow down the recovery.
Hospital etiquette also requires you to understand a few simple rules about waiting rooms. First, the rooms are there to be shared. This means you should keep it in the best possible condition so others can use it as well. Do not create trash, and if you do, find a place to dump it or take it with you. Do not take a million little items with you and don't crowd the tables or sofas.
Some hospitals don't allow cell phones inside, but even if they do, is good hospital etiquette to turn them off or at least put them in vibrating. The hospital is also not the right place to speak loudly or start a discussion. If you have something to say that cannot be expressed on a low voice, step out of the building. Finally, it is good hospital etiquette to be respectful to the staff. Nurses are often overworked and if they don't get back to you with an answer right away, it may be because they got delayed with a different request. Ask again if necessary, but be polite.