CONTRAINDICATION

In medicine, a 'contraindication' is a condition or factor that increases the risks involved in using a particular drug, carrying out a medical procedure or engaging in a particular activity.

★ An ''absolute contraindication'' is a condition that prohibits the use of a treatment altogether. For example, an untreated pneumothorax would be an absolute contraindication to hyperbaric oxygen therapy.

★ A ''relative contraindication'' weighs in against the use of a treatment when assessing its risk/benefit ratio. For example, a history of peptic ulcer is a contraindication towards taking aspirin. If, however, the benefit of using aspirin is seen as greater than the risk of a recurrence of the ulcer, and no reasonable alternatives are available, the treatment is still indicated.
The opposite of contraindication is indication.