Thirty-eight patients admitted to the Coronary Care Unit were interviewed to discover the natural history of their moods and to assess their level of understanding of their medical condition. A progression of moods from anxiety to denial to depression was noted. Only seven of 38 patients were found to have a good understanding of their illness. Several barriers to doctor-patient communication were identified, including patient's denial, patient's distractibility due to surroundings, patient's "wishfully hearing," doctor's unwarranted assumptions about the patient's understanding, doctor's overuse of medical terminology, and doctor's unawareness of patient's emotional state. Finally, four suggestions for improving total patient care in the Coronary Care Unit are proposed: (1) understand the natural history of patient mood and perceive where your patient is in the progression, (2) institute formal teaching on dealing with patients' moods for nursing and medical personnel, (3) be aware of, and deal with, the barriers to physician-patient communication, and (4) institute formal patient education programs to aid communication and understanding.