According to the University of Washington School of Medicine, the obligation for confidentiality is not an absolute one. There are legal regulations that limit a patient's right to privacy, as well as regulations that protect that right. The two main exceptions where you could break confidentiality are:
(1) Concern for a specific, identified person other than the patient (this could be a spouse or child, or it could be a person unrelated to the patient in any way).
(2) Concern for the welfare of the general public (this is usually seen if the patient is found to have a highly infectious or communicable disease).
While doctors have some leeway for breaking confidentiality, they must be sure to do so only under circumstances where they are legally able to justify their choice. Otherwise, they risk lawsuits and similar problems.
