Applying association rules in medical diagnosis can be used to assist physicians while curing patients. The general problem of the induction of reliable diagnostic rules is hard as, theoretically, no induction process can guarantee the correctness of induced hypotheses by itself. Practically, diagnosis is not an easy process, as it involves unreliable diagnosis tests and the presence of noise in training examples.

Nevertheless, association rules can be used to identify likely symptoms appearing together. A transaction, in this case, corresponds to a medical case, while symptoms correspond to items. When a patient is treated, a list of symptoms is recorded as one transaction.