Indications

Indications are the reasons or circumstances under which a particular medical action is appropriate. In clinical practice, an indication justifies performing a procedure or prescribing a treatment. The opposite concept is a contraindication, a factor that discourages or prohibits a course of action. The term derives from the Latin indicare, meaning to point out or designate.

Indications can be therapeutic or diagnostic. Therapeutic indications specify conditions for which a drug or procedure is considered beneficial, such as using antibiotics for confirmed bacterial infections or anticoagulation for atrial fibrillation with high stroke risk. Diagnostic indications refer to when a test or imaging study should be obtained to guide management, for example ordering a chest X-ray for suspected pneumonia or MRI for suspected optic neuritis. Indications are further described as absolute, where the action is clearly warranted, or relative, where benefits must be weighed against risks.

In pharmacology and regulatory practice, an indication is the disease or condition for which a drug is approved. On-label indications are those officially approved by authorities; off-label indications are uses not approved but supported by evidence or experience. Indication strength can vary by guideline, country, and patient factors.

Indications form a core part of clinical decision-making, integrated with patient preferences, risk assessments, comorbidities, and available resources. They are distinct from signs and symptoms, which are clinical manifestations reported or observed; indications describe the action to be taken based on those findings.