IMMUNOLOGY

Detailed explanation-1: -Polycythemia vera (pol-e-sy-THEE-me-uh VEER-uh) is a type of blood cancer. It causes your bone marrow to make too many red blood cells. These excess cells thicken your blood, slowing its flow, which may cause serious problems, such as blood clots. Polycythemia vera is rare.

Detailed explanation-2: -Erythrocytosis, sometimes called polycythaemia, means having a high concentration of red blood cells in your blood. This makes the blood thicker and less able to travel through blood vessels and organs.

Detailed explanation-3: -What causes polycythemia vera? Polycythemia vera is caused by a genetic change (mutation) that develops during your lifetime. It is not an inherited genetic disorder. In most cases it is not known why this happens.

Detailed explanation-4: -Polycythemia, or erythrocytosis, refers to an increase in the absolute red blood cell (RBC) mass in the body. In practice, this is reflected by an increase in hemoglobin levels, or hematocrit, over what is considered physiologic for the particular age and gender.

Detailed explanation-5: -The most common causes of secondary polycythemia include obstructive sleep apnea, obesity hypoventilation syndrome, and chronic obstructive pulmonary disease (COPD). Other causes include testosterone replacement therapy and heavy cigarette smoking.