Since 1948, the World Health Organization has been publishing the International Statistical Classification of Diseases and Related Health Problems (ICD), a coded system of causes of disease and death with an in-depth revision every 10-15 years. In its latest revision, the ICD-11 uses nomenclature characterizing old age as "initial and final geriatric periods," implying the medicalization of this stage of life, which has created confusion and sparked controversy. This article discusses the new nomenclature proposed, given the current knowledge about old age and the aging process and its most accepted definition. The ICD not only classifies diseases but periods of life and "health-related problems," and old age per se is not a health-related problem for many people at this stage of life. It is therefore essential to change or provide a more nuanced definition of the term "old age" in the ICD-11, so it is not perceived as a symptom, sign, or anomalous clinical outcome, and to introduce nomenclature that more accurately reflects pathological aging. Two terms that are enjoying growing experimental and bibliographic support are "fragility" and "loss of intrinsic capacity," which offer greater precision when defining the condition of a person who is not experiencing healthy aging.