Essential thrombocytopenia (ET) wani yanayi ne na likitanci wanda ke nuna raguwar adadin platelet (thrombocytopenia) a cikin jini, waɗanda ke da mahimmanci don daskarewar jini. Kalmar "mahimmanci" a cikin wannan mahallin yana nufin cewa ba a san musabbabin yanayin ba, maimakon nuna cewa yanayin yana da mahimmanci ko mahimmanci. ET wani nau'in neoplasm na myeloproliferative neoplasm (MPN), wanda rukuni ne na rikice-rikice da ke tattare da haɓakar ƙwayoyin jini ta hanyar kasusuwa.