This review article aims to summarize the major causes of thrombocytopenia and characterize the main general symptoms of thrombocytopenia. As well we summarize the diagnosis and treatment methods. We conducted the search using electronic biomedical databases such as; Medline, and Embase, for studies published up to September 2017 in the English language concerning the thrombocytopenia in general. Thrombocytopenia can either be primary or secondary, in that it could go along with a broad spectrum of syndromes and diseases and may be triggered by different systems. Trigger investigation and recognition might be important and sometimes life-saving as in TTP, heparin-induced thrombocytopenia, acute leukemia or perhaps severe ITP. Taking a detailed history and a thorough physical examination can give clues concerning possible underlying illness and clinical treatments. Cautious evaluation of the peripheral blood smear is necessary. When the differential diagnosis is problematic, sometimes a short trial of therapy could help to clarify the reason. For instance, it might be difficult to differentiate inherited thrombocytopenia (without a family history) from immune thrombocytopenia (ITP); in this example, intravenous immunoglobulin infusion will likely have no effect in inherited thrombocytopenia, however, will generally be useful in ITP.