Disorder	Findings or clues to diagnosis
Bleeding
Platelet disorders (quantitative)	Bleeding, bruising, petechia, or purpura Consider idiopathic thrombocytopenic purpura, thrombotic thrombocytopenic purpura, malignancy, viral disease
Platelet disorders (functional)	Consider in a patient with a lifelong history of bleeding despite negative laboratory work-up Consider glycoprotein disorders (Bernard-Soulier syndrome, Glanzmann thrombasthenia), storage pool disease, von Willebrand's disease If platelets are abnormally shaped, consider May-Hegglin anomaly, Wiskott-Aldrich syndrome
Hemophilia type A or B (factor VIII or IX deficiency) or other factor deficiencies	Classically presents with joint or soft-tissue bleeding; family history of bleeding in men (skipped generations)
Factor inhibitors	Presentation similar to hemophilia, but onset is typically sudden with no patient or family history of bleeding
Hereditary hemorrhagic telangiectasia	Telangiectasias over lips, tongue, nasal cavity, and skin; epistaxis
Vasculitis or cryoglobulinemia	Neuropathy; pulmonary-renal involvement; purpura
Leukemia	Abnormal complete blood count or peripheral blood smear
Disseminated intravascular coagulation	Bleeding from multiple sites; prolonged prothrombin time and partial thromboplastin time
Vitamin K deficiency	More common causes include malabsorption (bacterial overgrowth, celiac disease, chronic pancreatitis, inflammatory bowel disease, short-gut syndrome), poor diet (alcoholism, total parenteral nutrition) or drugs that bind vitamin K (cholestyramine [Questran]).
Bruising
Purpura simplex (easy bruising)	Typically found in women on the upper thighs and arms
Alcohol abuse	Social history
Abuse (including child abuse)	Atypical pattern of bruising or bleeding; bruises that pattern after objects; bruises in children who are not yet mobile; history that is inconsistent with the patient's injuries
Senile purpura	Dark ecchymosis in aged, thin skin; typically over extensor surfaces of forearms
Cushing's disease	Facial plethora; hirsutism; hyperglycemia; hypertension; poor wound healing; stria
Marfan's syndrome	Enlarged aortic root; eye involvement; mitral valve prolapse; scoliosis; pectus excavatum; stretch marks; tall and slim, with long limbs and digits
Vitamin C deficiency (scurvy)	Dietary history
Ehlers-Danlos syndrome or connective tissue diseases	Atrophic scarring or joint dislocations; hypermobile joints; skin hyperextensibility