In medicine,<unk>  (sometimes abbreviated<unk> x or ΔΔ) is the systematic method physicians use to identify the disease causing a patient's symptoms.
Before a medical condition can be treated, it must be identified.  In the process of listening to a patient's complaints, examining the patient, and taking the patient's personal, family and social history, the physician makes a mental list of the most likely causes. The doctor asks additional questions and performs tests to eliminate possibilities until he or she is satisfied that the single most likely cause has been identified.
Once a working diagnosis is reached, the physician prescribes a therapy. If the patient's condition does not improve, the diagnosis must be reassessed.  The method of<unk>  was first suggested for use in the diagnosis of mental disorders by Emil Kraepelin. It is more systematic than the old-fashioned method of diagnosis by gestalt (impression).
The term<unk>  also refers to medical information specially organized to aid in diagnosis, particularly a list of the most common causes of a given symptom, annotated with advice on how to narrow down the list.
Differential diagnosis
Diagnosis
Nursing diagnosis
Medical therapy template
Injury cover
Concussion diagnostic criteria
Etiology
Residency 