The document summarizes key aspects of haemostasis including the vascular, platelet and clotting phases. It describes tests used to diagnose bleeding disorders affecting primary (platelets) and secondary (clotting factors) hemostasis. Clinical features of platelet and coagulation disorders are compared. The implications of bleeding disorders for periodontal treatment are discussed, highlighting the need to modify procedures and use hemostatic measures depending on the nature and severity of the underlying condition.