kinda long. from the ama

Patient confidentiality
http://www.ama-assn.org/ama/pub/category/4610.html full article.

this is the first paragraph

Physicians have always had a duty to keep their patients' confidences. In essence, the physician's duty to maintain confidentiality means that a physician may not disclose any medical information revealed by a patient or discovered by a physician in connection with the treatment of a patient. In general, AMA's Code of Medical Ethics states that the information disclosed to a physician during the course of the patient-physician relationship is confidential to the utmost degree. As explained by the AMA's Council on Ethical and Judicial Affairs, the purpose of a physician's ethical duty to maintain patient confidentiality is to allow the patient to feel free to make a full and frank disclosure of information to the physician with the knowledge that the physician will protect the confidential nature of the information disclosed. Full disclosure enables the physician to diagnose conditions properly and to treat the patient appropriately. In return for the patient's honesty, the physician generally should not reveal confidential communications or information without the patient's express consent unless required to disclose the information by law. There are exceptions to the rule, such as where a patient threatens bodily harm to himself or herself or to another person.