In psychoanalytic theory, denial is a defense mechanism in which a person is faced with a fact that is too uncomfortable to accept and rejects it instead, insisting that it is not true despite what may be overwhelming evidence.
[2] Because the symptoms are so varied, and often have other potential explanations, the opportunity exists for the patient to deny the reality of the emergency, often with fatal consequences.
It is common for patients to delay recommended mammograms or other tests because of a fear of cancer, although this usually worsens the long-term medical outcome.
[3] Initial short-term denial can be a good thing, giving time to adjust to a painful or stressful issue.
[4] Some people who have been known to be in denial of historical or scientific facts accepted by the mainstream of society or by experts, for political or economic reasons, have been referred to as denialists[5] or true believers.