Erythrocytosis: Definition, Causes & Symptoms | Medical Definitions

Erythrocytosis is a combining form that means "excessive red blood cells". It is derived from the Greek word "erythros", which means "red", and "kytos", which means "cell". Erythrocytosis can be a symptom of a number of different conditions, including polycythemia vera, a bone marrow disorder that causes the body to produce too many red blood cells.