What causes a high red blood cell count?
A high red blood cell count may be a symptom of a disease or disorder, although it doesn’t always indicate a health problem. Health or lifestyle factors can cause a high red blood cell count.
Medical conditions that can cause an increase in red blood cells include:
- Heart failure, causing low blood oxygen levels
- Congenital heart disease (born with it)
- Polycythemia vera (a blood disorder in which the bone marrow produces too many red blood cells)
- Kidney tumors
- Lung disease, such as emphysema, COPD, pulmonary fibrosis (lung tissue becomes scarred)
- Hypoxia (low blood oxygen levels)
- Carbon monoxide exposure (usually related to smoking)
Lifestyle factors that can cause a high red blood cell count include:
- Smoking cigarettes
- Living at a high altitude
- Taking performance-enhancing drugs such as anabolic steroids (for example, synthetic testosterone) or erythropoietin