Abstract
Background and Objectives
Heparin is still a commonly used anticoagulant in prophylaxis and treatment of thromboembolic events. Heparin-induced thrombocytopenia (HIT) is a life-threating adverse drug reaction of heparin. The diagnosis of HIT is made based on two important criteria, firstly clinical evaluation and secondly laboratory testing. In this comprehensive review, the authors will emphasize the risk factors, clinical presentation, pathophysiology, diagnostic principals and treatment of HIT.
 
Materials and Methods
Our study method was based on the search in the PubMed Database by related key words like: "heparin", "heparin induced thrombocytopenia", "pathophysiology", "diagnosis" and “treatment” published during 1997 to 2018.
 
Results
The disease is still a life-threatening event caused by the creation of an antibody against the heparin-PF4 complex and, if platelets are activated, can lead to thrombotic events in patients. Laboratory diagnostic methods are important in excluding or confirming the diagnosis of HIT, especially in patients who are moderate or highly clinical probability of HIT suspected.
 
Conclusions 
Today, with a better understanding of the pathophysiology of the disease as well as the advances made in the speed and precision of laboratory diagnostic methods, an important development has occurred in the diagnosis of HIT.