Hematologic disorders affect the blood cells and bone marrow. Symptoms suggesting hematologic disorders include fatigue, paleness of the skin, bruising easily, bleeding under the skin (petechiae), prolonged bleeding time and the spontaneous formation of blood clots. Common hematologic disorders include anemia, thrombocytopenia (low platelets), leukopenia (low white blood cells), and blood clotting disorders (Protein C deficiency, Protein S deficiency, Factor deficiencies). Oncologic disorders of the hematologic system refer to malignant (cancer related) causes for any abnormalities in the hematologic system (lymphoma, leukemia, myeloma). General oncology includes the evaluation and treatment of solid tumors. Diagnostic testing for hematologic and oncologic disorders can include blood testing and possibly a bone marrow biopsy if indicated. Evaluation by a hematologist/oncologist should be considered at the suggestion of a primary care physician or if any of the above listed symptoms occur without a clear etiology.