4T

4T is a designation used in several fields, and there is no single, universal meaning. In engineering and automotive contexts, 4T commonly denotes four-stroke engines, contrasting with 2T for two-stroke designs. The label is used in product specifications and marketing to indicate the engine cycle rather than power output or displacement.

In medicine, 4T (often written 4Ts) is a clinical scoring system used to estimate the probability of heparin-induced thrombocytopenia in patients who have received heparin. The four components are Thrombocytopenia, Timing of the platelet count fall, Thrombosis, and Other causes. Clinicians use the score to guide testing and treatment decisions, recognizing that it has limitations and should be combined with laboratory confirmation.

Beyond these uses, 4T serves as a generic abbreviation or model code in various domains, including education, technology, and industry, where the meaning depends on the context. It may denote a project phase, a product line, or a spatial/temporal framework. Because of this variability, it is important to consult domain-specific documentation to determine what 4T stands for in a given setting.

See also: four-stroke engine, HIT scoring.