Hematology Glossary
A
Acute: Refers to a disease that begins suddenly and/or progresses quickly.
Allogeneic: Refers to blood, stem cells, bone marrow, or other tissue transferred from one person to another.
Anemia: A blood condition in which a person either does not have enough red blood cells or has red blood cells that do not function properly.
Antibody: A protein found in the blood that recognizes and binds to other substances. Helpful antibodies neutralize or destroy targets like viruses or bacteria.
Anticoagulant: A drug that prevents blood clots from forming.
Antigen: A marker protein on cells of the body or foreign substances like viruses or bacteria.
Artery: A muscular vessel that carries oxygen- and nutrient-rich blood under high pressure from the heart to other parts of the body.
Arterial thromboembolism: A clot that forms within an artery and may obstruct the flow of blood.
Autologous: Refers to blood or other tissue derived from a person’s own body.
B
B lymphocyte: A type of white blood cell that produces antibodies.
Basophil: A type of white blood cell that may increase with bone marrow damage or allergic reactions.
Benign: Refers to a non-cancerous disease that does not spread throughout the body.
Bleeding disorder: The clinical problem resulting when blood does not clot properly.
Blood: The specialized fluid in your body with many functions, including carrying oxygen and nutrients to tissues.
Blood banking: The process of collecting, separating, and storing blood products.
Blood cancer: A condition affecting the blood, bone marrow, or lymph nodes with uncontrolled growth of abnormal blood cells.
Blood smear/film: The glass slide on which doctors examine blood cells under the microscope.
Blood transfusion: A procedure in which blood from a donor is transferred to another person.
Bone marrow: The soft, spongy tissue inside bones where blood cells are produced.
Bone marrow transplantation: The transfer of healthy bone marrow cells into a person whose marrow is damaged.
C
Cancer: An abnormal and uncontrolled growth of cells.
Capillaries: The body’s smallest blood vessels, connecting arteries to veins.
Chimeric antigen receptor (CAR) T-cell therapy: A cancer immunotherapy involving reengineered T-cells.
Chemotherapy: A medical treatment for the destruction of cancer cells.
Chronic: Refers to a slowly progressing disease.
Circulatory system: The heart and network of blood vessels responsible for transporting blood throughout the body.
Clinical trial: A research study involving human volunteers to evaluate new treatments.
Clot: A clump of platelets and blood proteins forming a plug to prevent excessive bleeding.
Coagulation: The process by which blood clots.
Complete blood count (CBC): A test providing information about the types and numbers of cells in one’s blood.
D
Deep vein thrombosis: A type of blood clot that forms in a major vein of the leg or arm.
Defibrillation: The use of electric shock to restore normal heart rhythm.
E
eosinophil: a type of white blood cell that mediates allergic reactions and defends the body from infection by parasites and bacteria
erythrocyte: also called the red blood cell; the most abundant cell in the blood whose primary role is to carry the protein hemoglobin that transports oxygen from the lungs to the rest of the body
erythropoietin: a hormone produced primarily by the kidneys that controls the production of red blood cells
F
factor: a protein in the blood that is needed to form a blood clot
ferritin: a form of iron that is stored in the liver and released as needed to make new red blood cells
fibrin: a threadlike protein that supports the formation of blood clots and provides the initial structure upon which new tissue can form at the site of an injury
G
granulocyte: a type of white blood cell that includes neutrophils, eosinophils, and basophils.
H
hematocrit: the percentage of the whole blood volume that is made up of red blood cells; it is abbreviated Hct
hematologic malignancy: a disease (also known as a blood cancer) affecting the blood, bone marrow, or lymph nodes in which normal blood production and function is interrupted by the uncontrolled growth of an abnormal type of blood cell
hematologist: a physician who specializes in researching, diagnosing, and treating blood disorders
hematology: the scientific study of blood and blood-forming tissues
hematopoiesis: the process by which the body produces new blood cells
hematopoietic stem cell: a cell that can develop into any type of blood cell; often abbreviated HSC
hemoglobin: a protein in red blood cells that carries oxygen to other cells in your body; often abbreviated HGB, Hb, or Hg
hemoglobinopathy: a blood disease resulting from structural differences in hemoglobin produced by the body
hemophilia: a congenital or inherited bleeding disorder caused by a shortage of clotting factors in the blood
I
idiopathic: refers to a disease or condition without a known cause
immune system: the network of cells, tissues, and organs that defend the body from infection and disease
intravascular hemolysis: a condition in which red blood cells break down in the blood stream
iron: a mineral that is important for maintaining many body functions and an integral part of hemoglobin, the molecule in your blood that carries oxygen to the tissues of the body
L
leukemia: a type of cancer found in the blood and bone marrow that is caused by the production of abnormal white blood cells
leukocyte: a type of cell (also known as a white blood cell or WBC) in the blood that is primarily responsible for protecting the body from infection; there are five major types of white blood cells (basophils, eosinophils, lymphocytes, monocytes, and neutrophils), each with special properties and functions
lymph node: small organs throughout the body that play a role in the immune system by filtering out foreign particles, such as viruses and bacteria
lymphocyte: a type of white blood cell that plays a role in the immune system; there are two main populations of these cells: T lymphocytes, which help regulate the function of other immune cells and directly attack infected cells and tumors, and B lymphocytes, which make antibodies.
lymphocytic: refers to a disease involving the abnormal growth of white blood cells called lymphocytes
lymphoma: a type of blood cancer that occurs when abnormal lymphocytes (a type of white blood cell) multiply and collect in the lymph nodes and other tissues, impairing the function of the body’s immune system
M
malignant: refers to a cancerous tumor or disease that may spread or metastasize to other parts of the body
monocyte: a type of white blood cell that ingests bacteria and foreign particles
myelogenous: refers to a disease of the blood-forming cells in the bone marrow
myeloma: a cancer of plasma cells (white blood cells that produce disease- and infection-fighting antibodies)
N
neutropenia: a low number of granulocytes (white blood cells that fight infection)
neutrophil: the most common type of white blood cell, which helps the body fight infection
O
oncology: the scientific study of cancer
P
peripheral blood: blood that is circulating through the body’s blood vessels and heart
peripheral blood stem cells: rare cells in the peripheral blood that have the unique property of self-renewal as well as the ability to develop into other types of cells; these cells may be increased and used as the source of cells for a stem cell transplant
plasma: the liquid component of blood that transports blood cells throughout the body along with nutrients, waste products, antibodies, proteins, and chemical messengers such as hormones
plasma cell: a type of white blood cell that produces disease- and infection-fighting antibodies
platelet: a small cell fragment (also known as a thrombocyte) involved in the blood’s clotting process
platelet count: part of the complete blood count, a blood test used to evaluate bleeding and clotting disorders
pulmonary embolism: a dangerous condition that occurs when a clot in a vein detaches from the blood vessel in which it formed and travels through the heart to the lungs where it becomes wedged, preventing adequate blood flow
R
radiation therapy: a treatment used to destroy cancer cells with high-energy rays, such as x-rays or gamma rays
red blood cell: the most common blood cell; it carries the protein hemoglobin, which transports oxygen from the lungs to the rest of the body; red blood cells are also known as erythrocytes or RBC
S
sickle cell anemia: a congenital inherited blood disorder characterized by a different type of hemoglobin that causes red blood cells to become rigid and sickle-shaped
stem cell: a cell that has the unique property of self-renewal as well as the ability to develop into other types of specialized cells, such as blood cells
T
T lymphocyte: a type of white blood cell (also known as a T cell)that helps protect the body against infection and cancer; some T cells can also release substances to attract other white blood cells and can regulate the activity of other immune cells
targeted therapy: a type of treatment that destroys cancer cells without harming normal cells
thalassemia: an inherited congenital blood disorder that results in the decreased production of hemoglobin and red blood cells
thrombectomy: the surgical removal of a blood clot
thrombocyte: a small cell fragment (also known as a platelet) involved in the blood’s clotting process
thrombosis: excess clotting, which may block veins or arteries
thrombus: a clump of platelets and blood proteins (also known as a clot) that form a plug at the site of an injured blood vessel to prevent excessive bleeding
transferrin: a protein that attaches to iron in the blood stream and delivers it to the liver
tumor: an abnormal mass of cells, which can be cancerous or benign
V
vein: a vessel that carries blood low in oxygen away from the body’s organs and back to the heart
venous thromboembolism: a clot that forms within a vein and may obstruct the flow of blood
von Willebrand disease: a bleeding disorder caused by decreased or abnormal von Willebrand factor, a blood protein that helps the blood to clot; it may be inherited or acquired
W
white blood cell: a type of blood cell (also known as a leukocyte) that is primarily responsible for protecting the body from infection; there are five major types of white blood cells (basophils, eosinophils, lymphocytes, monocytes, and neutrophils), each with special properties and functions
white blood cell count (WBC): a bloodtest that measures the number of white blood cells to help detect problems in the body’s immune system
