Polycythemia

enUK

polycythemia

(pŏl'ēsīthē`mēə), condition characterized by an increase in the production of red blood cells, or erythrocytes, in the blood. Primary polycythemia, also called erythremia, or polycythemia vera, is a chronic, progressive disease, most common in middle-aged men. It is characterized by overgrowth of the bone marrow, abnormally increased red blood cell production, and an enlarged spleen. Symptoms, include headache, inability to concentrate, and pain in the fingers and toes. There is a danger of blood clotting or hemorrhage (see thrombosisthrombosis
, obstruction of an artery or vein by a blood clot (thrombus). Arterial thrombosis is generally more serious because the supply of oxygen and nutrition to an area of the body is halted.
..... Click the link for more information. ). Primary polycythemia is treated by radiation, periodic removal of some blood (phlebotomy), or chemotherapy with antimetabolite drugs, e.g., CytoxanCytoxan
, trade name for the drug cyclophosphamide, used to inhibit growth of tumors and rapidly proliferating cells. It is used in the treatment of leukemia, Hodgkin's disease, and lymphosarcoma and other solid tumors.
..... Click the link for more information. . In secondary polycythemia, or erythrocytosis, the proliferation of red blood cells results from the body's attempt to compensate for other conditions, such as prolonged lack of oxygen at high altitudes or chronic lung or heart insufficiency. Certain tumors are also associated with increased red blood cell production. In secondary polycythemia the treatment is directed toward the underlying cause.

Polycythemia

an increase in the total quantity of blood in the human body. A distinction is made between polycythemia vera, in which the increase in erythrocytes, up to 8–10 million in 1cu mm of blood, is greater than the increase in the total volume of blood plasma, and hypervolemia, which is characterized chiefly by an increase in the volume of plasma. The latter may be of cardiac origin or may be due to water retention in the vascular system after copious drinking. The normal ratio of the volume of blood cells to that of plasma is 45:55.

Polycythemia

an increase in the number of erythrocytes in the blood. Spurious, or relative, polycythemia results from a reduction in the volume of blood plasma and is caused by loss of fluid, as from heavy perspiration or from diarrhea. Secondary polycythemia is characterized by an absolute increase in the number of erythrocytes, as with oxygen deficiency in the mountains, heart disease, or pulmonary emphysema. Secondary polycythemia accompanied by an increase in the volume of blood plasma is called polycythemia vera, or erythremia.

polycythemia

[‚päl·i‚sī′thē·mē·ə] (medicine) A condition characterized by an increased number of erythrocytes in the circulation.

polycythemia

enUK

polycythemia

[pol″e-si-the´me-ah] an increase in the total red blood cell mass of the blood; called also erythrocythemia, hypercythemia, and hypererythrocythemia.
There are two distinct forms of the disease: Primary polycythemia (polycythemia vera) is a myeloproliferative disorder of unknown etiology. It is characterized by hyperplasia of the cell-forming tissues of the bone marrow, with resultant elevation of the erythrocyte count and hemoglobin level, and an increase in the number of leukocytes and platelets.
Secondary polycythemia is a physiologic condition resulting from a deficient oxygen supply to the tissues. The body attempts to compensate for the deficiency by manufacturing more hemoglobin and erythrocytes. Living at high altitudes can produce polycythemia, as can severe chronic lung and heart disorders, especially congenital heart defects.
Absolute polycythemia refers to an increase in red cell mass from any cause. Relative polycythemia refers to a loss of plasma volume causing an elevated hematocrit.Symptoms. The symptoms of primary and secondary polycythemia are much the same. The increased erythrocyte production results in thickening of the blood and an increased tendency toward clotting. The viscosity of the blood limits its ability to flow properly, so that the supply to the brain and other vital tissues is diminished. This may cause sluggishness, irritability, headache, dizziness, fainting, disturbances of sensation in the hands and feet, and a feeling of fullness in the head. There may be episodes of acute pain as spontaneous clots occur in the blood vessels. The spleen becomes enlarged and the smaller veins become more prominent, so that the skin has a bluish hue. The secondary form is often accompanied by enlargement of the tips of the fingers (clubbing).Treatment. Treatment of polycythemia vera is aimed at reducing the red cell count and decreasing the blood volume. Mild cases can be managed by periodic phlebotomy. More serious cases may require myelosuppressive therapy; interferon and large-dose aspirin therapy may also be used. Research on treatment modalities is ongoing. In secondary polycythemia, successful treatment of the causative illness will relieve the polycythemia.

hy·per·cy·the·mi·a

(hī'pĕr-sī-thē'mē-ă), The presence of an abnormally high number of red blood cells in the circulating blood.
See also: polycythemia. Synonym(s): hypererythrocythemia, polycythemia [hyper- + G. kytos, cell, + haima, blood]

polycythemia

(pŏl′ē-sī-thē′mē-ə)n. A condition characterized by an abnormally high number of red blood cells in the blood.

polycythemia

(pŏl′ē-sī-thē′mē-ə)n. A condition marked by an abnormally large number of red blood cells in the circulatory system.

polycythemia

Any ↑ RBC mass. See Relative polycythemia, Secondary polycythemia. Polycythemia types Relative RBC mass is above normal but not pathologic. See Relative polycythemia. Secondary to various physiopathologic mechanisms, usually hypoxia or ↑ erythropoietin secretion Neoplastic, ie polycythemia vera, see there &nbsp. ;.

pol·y·cy·the·mi·a

(pol'ē-sī-thē'mē-ă) An abnormal increase in the number of red blood cells.
Synonym(s): erythrocythemia, polycythaemia. [poly- + G. kytos, cell, + haima, blood]

polycythemia

(pol?e-si-the'me-a) [ poly- + cyto- + -emia] An excess of red blood cells. In a newborn, it may reflect hemoconcentration due to hypovolemia or prolonged intrauterine hypoxia, or hypervolemia due to intrauterine twin-to-twin transfusion or placental transfusion resulting in delayed clamping of the umbilical cord. Synonym: erythrocytosis

Chuvash polycythemia

An autosomal recessive erythrocytosis in which patients respond to normal oxygen levels as if they were in an hypoxic environment and make more red blood cells than are needed. ASludging of blood, pulmonary hypertension, and vascular infarcts are common sequelae.

relative polycythemia

A relative (rather than an absolute) increase in the number of erythrocytes due to a reduction of plasma volume, e.g., in patients with burns or dehydration.

secondary polycythemia

Polycythemia due to a physiological condition that stimulates erythropoiesis, e.g., lowered oxygen tension in blood.

spurious polycythemia

Gaisböck syndrome.

POLYCYTHEMIA VERA: peripheral blood smear in polycythemia vera (X 400)

POLYCYTHEMIA VERA

polycythemia vera

A chronic, life-shortening myeloproliferative disorder due to the reproduction of a single stem-cell clone. It is characterized by proliferation or hyperplasia of all bone marrow cells, with an increase in red blood cell mass and hemoglobin concentration that occurs independently of erythropoietin stimulation. Synonym: erythremiaillustration;

Symptoms

Usually occurring between ages 40 and 60 and most common in males with Jewish ancestry, polycythemia seldom affects children or those of African ancestry. Weakness, fatigue, headache, blood clotting, vertigo, tinnitus, irritability, dyspnea, visual disturbances, flushing of face, redness, or ruddy cyanosis, pruritus, ecchymosis, hypertension, epigastric distress, weight loss, and pain in joints or extremities occur commonly. The bone marrow shows uncontrolled, rapid cellular reproduction and maturation (increased cellularity). Peptic ulcers are often reported.

Treatment

The mainstay of patient care is the reduction in red blood cell mass with recurrent phlebotomy to lower the hematocrit to 45% or less. Vitals signs are monitored during and after phlebotomy, and the patient is provided with oral fluids and protected from orthostatic hypotension. The symptoms and the need to seek medical attention when signs and symptoms of bleeding and thrombus formation occur are explained to the patient. Rest should be balanced with exercise, but the patient should be advised that activity and ambulation help prevent thrombotic complications. Reassurance and support are provided to the patient and family, and opportunities are provided for questions and discussion of concerns. Patients who have a history of blood clotting or very high platelet counts are treated with myelosuppressive drugs, such as hydroxyurea. During myelosuppressive therapy the patient is informed about adverse effects that may occur, assessed for leukopenia and thrombocytopenia, and protective measures are taught and instituted.

illustration

Polycythemia

A condition characterized by an overabundance of red blood cells.Mentioned in: Hypercoagulation Disorders

pol·y·cy·the·mi·a

(pol'ē-sī-thē'mē-ă) An abnormal increase in the number of red blood cells.
Synonym(s): erythrocythemia, polycythaemia. [poly- + G. kytos, cell, + haima, blood]

polycythemia

pol·y·cy·the·mi·a

Polycythemia

polycythemia

Polycythemia

Polycythemia

polycythemia

polycythemia

polycythemia

hy·per·cy·the·mi·a

polycythemia

polycythemia

polycythemia

pol·y·cy·the·mi·a

polycythemia

Chuvash polycythemia

relative polycythemia

secondary polycythemia

spurious polycythemia

polycythemia vera

Symptoms

Treatment

Polycythemia

pol·y·cy·the·mi·a

polycythemia

Words related to polycythemia

noun a disorder characterized by an abnormal increase in the number of red blood cells in the blood

Related Words