Hematology: Definition, Blood Anatomy, Study Areas, Testing and Scope

It is the science or study of blood, blood-producing organs, and blood diseases.

In the medical field, hematology includes the treatment of blood disorders and malignant tumors, including the types of hemophilia, leukemia, lymphoma, and sickle cell anemia.

Hematology is a branch of internal medicine that deals with the physiology, pathology, etiology, diagnosis, treatment, prognosis, and prevention of blood-related disorders.

Hematologists focus primarily on the lymphatic organs and bone marrow and can diagnose blood count irregularities or platelet irregularities. Hematologists treat organs that are fed by blood cells, including the lymph nodes, spleen, thymus, and lymphoid tissue.

Blood anatomy

Blood is made up of several parts, including red blood cells, white blood cells, platelets, and plasma. Red blood cells, which make up about 45% of whole blood, carry oxygen from the lungs to body tissue.

They also carry carbon dioxide into the lungs to exhale. They are disc-shaped and are produced in the bone marrow. White blood cells, which are also made in the marrow, help fight infection. Together with platelets, they make up less than 1% of whole blood.

Platelets are small colorless fragments that bind and interact with clotting proteins to stop or prevent bleeding. They are also produced in the bone marrow.

Plasma is the fluid part of the blood. Composed of 92% water, it also contains vital proteins, mineral salts, sugars, fats, hormones, and vitamins.

Study areas

The four main areas of study in hematology include hemoglobinopathy, hematologic malignancies, anemia, and coagulopathy.

Hemoglobinopathy is the study of abnormality in the globin chains of hemoglobin molecules. In addition to sickle cell anemia, thalassemia (also known as erythropoiesis) is part of hemoglobinopathy.

The area of ​​hematologic malignancies refers to the diagnosis and treatment of cancers of the bone marrow, blood, and lymph nodes. Myeloma is a type of hematologic malignancy, along with leukemia and lymphoma. Other disorders treated by a hematologist include arterial thromboembolism, deep vein thrombosis, and neutropenia.

Training and work

Hematologists initially complete a four-year medical degree and this is followed by three to four years in an internship or residency program. From then on, they spend two to three more years learning how to diagnose and treat blood disorders.

Extensive first-hand hands-on experience at a recognized training center provides hematologists with expertise in the following areas:

  • The cause of abnormalities in blood formation and other blood disorders.
  • Diagnosis of various blood-related disorders and cancers using laboratory tests and examinations.
  • The care and treatment of patients with diseases of the blood or hematological diseases.

Oncological hematology

Although hematologists work in conjunction with experts from various medical and surgical specialties, hematology is often associated with oncology. Hematologists and oncologists work together to care for adults and children with cancers of the blood and bone marrow, including leukemia and lymphoma.

Hematology tests

One of the most common hematology tests is the complete blood count or CBC. This test is often done during a routine exam and can detect anemia, clotting problems, blood cancer, immune system disorders, and infections.

Other hematology tests include:

  • Blood chemistry test.
  • Blood enzyme test.
  • Blood tests to assess the risk of heart disease.


Here are some of the conditions / diseases that hematologists deal with:

  • Diseases such as hemophilia, idiopathic thrombocytopenic purpura, von Willebrand disease (which are platelet and bleeding disorders).
  • Malignant lymphomas
  • Iron deficiency anemia and other types of anemia, such as sickle cell anemia or trauma-related anemia.
  • Leukemia.
  • Myelodysplastic syndromes.
  • Polycythemia or excessive production of red blood cells.
  • Myelofibrosis
  • Multiple myeloma.
  • Hemoglobinopathies such as thalassemia and sickle cell disease.

Here are some of the procedures that hematologists handle:

  • Blood transfusion.
  • Bone marrow stem cell transplant.