subchronische

Subchronische, often rendered as subchronic in English, is a term used in medicine, toxicology and related fields to describe effects, exposures or conditions of intermediate duration—longer than acute but shorter than chronic. The use of the term varies by discipline and country, and its exact boundaries are not rigid.

In toxicology, subchronic exposure refers to repeated contact with a substance over a middle-length period, typically weeks to months. A common reference in regulatory science is a 90-day (approximately three months) subchronic toxicity study in laboratory animals, used to identify potential health risks and target organs and to assess dose-response and reversibility. This is distinct from acute exposure, which is short-term, and chronic exposure, which extends over months or years.

In clinical medicine, subchronic may describe conditions or infections that persist beyond the immediate, short-term course but do not meet the formal criteria for chronic disease. The term is often replaced by more precise descriptors in modern practice, such as subacute or episodic, depending on the disease process and duration.

Etymology: from Latin sub- “under, below” plus chronicus, indicating a state intermediate between acute and chronic. It is widely used in Dutch, English and other languages with similar meanings, but the preferred wording can differ by region and guideline.

See also: acute, subacute, chronic, toxicity, exposure.