Polycythaemia is
(a) WBC increase
(b) RBC increase
(c) Platelet increase
(d) All of the above

Hint: They are also called erythrocytes, are cells that circulate in the blood and carry oxygen throughout the body. The erythrocytes count totals the number of red blood cells that are present in your sample of blood.

Complete step by step answer:
Polycythemia is regarded as a disease state during which the proportion of blood volume that's occupied by red blood cells increases. Blood volume proportions are often measured as hematocrit levels. It is often because of a rise in the number of red blood cells or to a decrease within the volume of plasma. The increase in the red blood cells consequently leads to an increased concentration of hemoglobin in the blood supply. Clots, heart attacks and strokes are the possible consequences of an increased hemoglobin level.
So, the correct answer is, ‘RBC increase.’

Additional information:
- When the RBCs are developing in the red bone marrow, they do have nuclei. However, these nuclei are ejected from the cells when they enter the bloodstream in a process known as enucleation.
- In camels, the process of enucleation does not take place hence they have nucleated red blood cells.
- In camels, the erythrocytes or red blood cells are oval because the oval shape of the cell can circulate through thick blood and can expand during dehydration.
- The camel’s RBCs can be aligned in the various directions of the blood without any complications.

Note:
- The red blood cells of camels can expand to 240% of their initial size which as a result can hydrate their blood much more when allowed to drink water.
- In mammals, the RBC is generally binucleated, without the nucleus and the mitochondria.
- In mammals, the red blood cells do not contain any cell organelles making it rich in hemoglobin.