Information about one's health is valuable and medical personnel must not reveal it to third parties. Violations of confidentiality can have serious consequences. For example, public figures do not want it publicly known when they suffer from a sexually transmitted disease, and can be blackmailed with this information. Insurance companies can refuse to cover clients if they find out that the client has a chronic illness.
It may become relatively easy to obtain unauthorized access to medical records if they are stored on a computer network and a password controls entry.