ICd

ICD, an abbreviation with several distinct uses in medicine, technology and classification, most commonly denotes the International Classification of Diseases and the implantable cardioverter‑defibrillator.

The International Classification of Diseases (ICD) is a globally endorsed diagnostic tool published by the World Health Organization. It provides a standardized system of codes for diseases, signs, symptoms, abnormal findings, and external causes of injury or disease. The classification facilitates epidemiological research, health management, and reimbursement processes across national health systems. Since its first edition in 1893, the ICD has evolved through successive revisions, with ICD‑10 and the more recent ICD‑11 being the most widely implemented. Each revision expands the code set, refines disease definitions, and incorporates advances in medical knowledge, while maintaining compatibility with earlier versions to support longitudinal health data analysis.

In cardiology, ICD refers to the implantable cardioverter‑defibrillator, a device placed under the skin and connected to the heart via leads. Its purpose is to detect and terminate life‑threatening ventricular arrhythmias by delivering electrical shocks or anti‑tachycardia pacing. Indications include prior cardiac arrest, sustained ventricular tachycardia, and certain inherited channelopathies. Clinical trials have demonstrated reductions in sudden cardiac death rates among eligible patients, although device implantation carries risks such as infection, lead malfunction, and inappropriate shocks.

Other specialized uses of the acronym include interstitial cystitis, a chronic bladder condition, and industrial control diagrams in engineering. Context determines the appropriate meaning, and each usage reflects the broad interdisciplinary relevance of the term ICD.