What is it?

Polycythemia is an increased amount of red blood cells in the blood stream. This causes our blood to thicken or bocome more viscose, which may cause variouse symptoms and complications. Red blood cells are responsible for carrying oxygen to the cells in our body. Thickened blood flows more slowly, thus the amount of oxygen reaching the tissues is reduced. In addition, thickened blood is more prone to blood clot formation. These clots can block blood flow to the brain or other organs, causing a stroke or even death. Risk factors include obesity, exessive alcohol use, hypertension and smoking.

The causes are commonly divided into primary and secondary. Primary polycythemia is caused due to a problem in the red blood cell producing cells in the bone marrow whereas secondary polycythemia is caused by another underlying condition. It is important to know that volume depletion may also cause polycythemia. This polycythemia can be reversed by giving fluids.

1. Primary polycythemia- The most common cause for primary polycythemia is a condition called polycythemia vera. This is a type of blood cancer that causes over production of red blood cells.
2. Secondary polycythemia- Common causes for secondary polycythemia include sleep apnea, obesity, smoking, hypoventilation and chronic obstructive pulmonary disease. High altitude may also cause secondary polycythemia. Since our red blood cells are responsible for carrying oxygen to the cells in our body, and oxygen levels are lower in high altitude, our body compensates by over-production of red blood cells. Some cancers may also cause polycythemia.