Hematology is the branch of medical practice concerned with conditions of the blood.
These conditions range from benign problems such as anemia or coagulation disorders, to the malignant conditions of blood and lymphatic organs such as leukemia or lymphoma.

Anemia  

A decrease in the red blood cells and, therefore, the hemoglobin concentration of the blood. This results in a decreased capacity of the blood to carry oxygen

Anemia, iron deficiency  

a type of anemia caused by low or absent iron stores. Iron deficiency anemia is the most common form of anemia. Iron is an essential component of hemoglobin, the oxygen-carrying pigment in the blood. Iron is normally obtained through the food in the diet and by the recycling of iron from old red blood cells.

Myeloma  

A malignancy of plasma cells. The disease usually starts in the marrow. The malignant plasma cells make a monoclonal immunoglobulin, the detection of which may be very helpful in diagnosis. The cells secrete chemicals that stimulate the overactivity of bone-dissolving cells, called osteoclasts, leading to osteoporosis and weak bones that fracture easily.

Myelodysplasia or Myelodysplastic syndrome  

A group of diseases that originate in a bone marrow stem cell. About half of the cases are mild to moderate anemias accompanied by mild to moderately reduced white cell and platelet counts. Often, these are not progressive but they have a heightened propensity to evolve into acute myelogenous leukemia. The other half of the cases are a type of slow-growing leukemia that may be associated with severe white cell and platelet deficits. Many of the patients affected require transfusion therapy; have a propensity to infection or to bleeding, and frequently progress to more overt leukemia. These disorders can occur at any age but are most common after age 60.

Polycythemia (rubra vera)  

A clonal disease characterized by the over-production of red blood cells by an abnormal stem cell in the marrow. The hallmark of the disease is an increased number of red cells. The number of white blood cells and platelets are also usually increased. The accumulation of red cells is progressive and usually requires treatment at the time of diagnosis. The increase in white cells is usually slight but the increase in platelets may become troublesome and require treatment as well.

Von Willebrand’s disease  

A congenital or acquired bleeding disorder, characterized by a prolonged bleeding time and, epistaxis (nosebleeds) and increased bleeding after trauma or surgery.

HITT (heparin-induced thrombocytopenia)

This is a very unusual condition in which the body’s immune system paradoxically effects a state of Hypercoagulability in response to exposure to heparin (a blood thinner). Compounding the bizarre picture is the presence of thrombocytopenia (low platelets).

Hypercoagulability  

A condition in which the normal balance of clotting blood and dissolving blood clots is shifted towards the clotting of blood.

Myeloproliferative Disorders  

A group of disorders characterized by the over-production of blood cells by the marrow. (See essential thrombocythemia, polycythemia vera, chronic myelogenous leukemia.)

Low platelet count or “Thrombocytopenia”  

May be associated with many other blood conditions or may be present as a disease itself.

Clotting Factors  

Chemical constituents of the blood, which in response to blood vessel injury, interact in sequence to result in a clot.

Coagulation  

The process of clotting of the blood. A complex reaction depending on a series of sequential interactions of blood clotting proteins and the platelets in the blood. The primary aim of blood coagulation is of course to stop hemorrhage, but when it occurs in inappropriate places or at the wrong times it may lead to serious complications.